FSLogix Blog articles

Action required: Windows Kerberos hardening (RC4) may affect FSLogix profiles on SMB storage

Jason_Parker — Fri, 27 Mar 2026 20:14:42 GMT

Beginning with the April 2026 Windows cumulative update, Kerberos default behavior changes: when an Active Directory object’s encryption type is not explicitly set (null), Windows will default to AES-SHA1 instead of legacy defaults that often resulted in RC4. This is a Windows platform security change. Azure Virtual Desktop service behavior is not being modified.

This may impact FSLogix customers (Azure Virtual Desktop and non-AVD) when FSLogix profile storage depends on SMB file shares integrated with Active Directory. If a dependent system (file server, NAS, or service account configuration) does not support AES-SHA1 for Kerberos, authentication may fail.

You may be impacted if:

You use Kerberos-based access to SMB storage for FSLogix profiles, and
Kerberos encryption settings are RC4-only or unset (null) for relevant AD objects or service accounts.

When will this happen:

April 2026: Enforcement Phase with manual rollback: Default Kerberos behavior changes so domain controllers use AES‑SHA1-only encryption for accounts without explicit encryption type settings, and Enforcement mode is enabled by default on Windows domain controllers. Audit mode remains available as a manual rollback option until July 2026.
July 2026: Enforcement Phase: Audit mode is removed, leaving Enforcement mode as the only option.

What you should do now:

Identify RC4 usage and null encryption settings for AD objects tied to SMB access (including FSLogix profile storage).
Update configurations to support and prefer AES-based Kerberos encryption (AES-SHA1).
Validate end-to-end sign-in and FSLogix profile access for your AVD and non-AVD environments.

Resources:

Troubleshoot Azure Files identity-based authentication and authorization issues (SMB) - Azure | Microsoft Learn
Read the full hardening guidance: How to manage Kerberos KDC usage of RC4 for service account ticket issuance changes related to CVE-2026-20833.
Learn about RC4 usage in Windows and its risks: Detect and remediate RC4 usage in Kerberos.
Learn more about the related vulnerability: CVE-2026-20833.
Windows Server Blog: Beyond RC4 for Windows authentication

FSLogix Release 25.06 is now generally available!

Jason_Parker — Tue, 08 Jul 2025 17:42:47 GMT

This latest release is focused on enabling compatibility and support for customers who are migrating their users from Microsoft Outlook (classic) to the modernized Microsoft Outlook for Windows. We included a minor fix and added 1 new item to our known issue page.

FSLogix Release Notes - FSLogix | Microsoft Learn

What's new

Support, data roaming, and application registration for Microsoft Outlook for Windows (MSIX version).
- Enabled special handling for the registration of the MSIX package family in both Profiles and ODFC.
- Supports redirections of the application data for ODFC containers.
- Allows coexistence between classic and Outlook for Windows under a single configuration setting.

Fixed issues

Fixed an issue where FSLogix attempted to look up a user token before it was initialized during profile load.

What's next

If you're not in our Customer Connection Program, I'd encourage you to check out my previous blog post: FSLogix is now part of the Microsoft Management Customer Connection Program (MM CCP)! The MM CCP is your place to gain access to our early access releases, communicate directly with the product team and chat with other customers in the program.

FSLogix support for virtual machine hibernation
Potential update for the GPO known issue

FSLogix Release 25.04 is now generally available!

Jason_Parker — Tue, 08 Apr 2025 18:09:52 GMT

While we strive to provide quality updates and validate all scenarios, some issues are challenging to validate prior to release. We reviewed many cases and heard your issues over social media. We continue to look for ways to improve the product and our release stability. We are looking forward to your feedback and comments.

FSLogix Release Notes - FSLogix | Microsoft Learn

Fixed Issues

FSLogix containers don't detach and prevent users from signing into a new session.
FSLogix Rules don't apply to users as expected.
FRXShell rule fails clean-up and prevents all user sign ins.
After signing in, user receives an error message that the Recycle Bin is corrupted.
Searchindexer.exe (frx_usermode_x64.dll) crashing in Windows Server 2016.

Known Issues

The following are the outstanding known issues that are still in progress:

ODFC settings applied to systems after ProfileLoad during sign in aren't applied to the user.
When signing into the same virtual machine between sessions, 'Resultant Set of Policy' (RSOP) or GPResult /R fails to find any data.
OneDrive is intermittently stuck at signing in on Windows Server 2019.

FSLogix Redirections and APP-V

Philip_McLoughlin — Sun, 23 Mar 2025 13:01:01 GMT

Hello FSlogix Nation,

Phil here from the FSLogix and APP-V Team.

You may recall I posted this Blog FSLogix and APP-V back in 2022 about APP-V and FSLogix and the need to Exclude the %localappdata%\Microsoft\Appv\Client folder and to Include AppData\Local\Microsoft\AppV\Client\VFS ?

Since the release of FSLogix 25.02 (3.25.202.4223) , there have been some reported issues for NEW FSlogix Profiles when having the following configuration:

APP-V Package published to a new user
New FSLogix Profile
A Redirections.xml containing:

<Exclude Copy="0">AppData\Local\Microsoft\Appv\Client</Exclude>

</Excludes>

<Include>AppData\Local\Microsoft\AppV\Client\VFS</Include>

</Includes>

FSLogix 25.02 (3.25.202.4223)

The issue is that a new user will not get any APP-V applications published to them on logon and subsequent logons. You may see an error when running a Publish Refresh:

Existing FSLogix Profiles are not impacted with the latest FSlogix Release FSLogix 25.02 (3.25.202.4223)

Since this article was first created June 2022, the issue has since been resolved in FSLogix 2210 (2.9.8361.52326)

There have been no reported issues with any version prior to FSLogix 25.02 (3.25.202.4223) with the redirections.xml containing the entries for APP-V.

To Resolve:

Remove these entries from the Redirections.xml and save.

<Exclude Copy="0">AppData\Local\Microsoft\Appv\Client</Exclude>

</Excludes>

<Include>AppData\Local\Microsoft\AppV\Client\VFS</Include>

</Includes>

The Profile however, even with the removal , will still have issues in getting APP-V applications.

You will need to create a new profile for that user , then FSLogix Profile users should be able to have APP-V apps published to them on logon.

Known issues in FSLogix 25.02

Jason_Parker — Mon, 17 Mar 2025 18:57:07 GMT

Our primary goal with any release is to ensure quality and reliability. This is a key focus area of our early access program, which is part of the Microsoft Management Customer Connection Program (MM CCP). We have been closely monitoring social media posts, customer-submitted cases, and our telemetry data to identify five known issues in the latest release.

We have updates in the pipeline to address these issues. Internal testing has already begun, and we plan to release an updated version to early access by the end of this week (March 21, 2025).

FSLogix containers do not detach and prevent users from signing into a new session

Description: Users were unable to sign into a new session because FSLogix containers did not detach properly.

Cause: Unhandled exceptions were causing a break in code flow that would normally continue and correctly detach an FSLogix container.

FSLogix Rules do not apply to users as expected

Description: Users were not correctly assigned to rules resulting in rules not working as expected.

Cause: Prior to 25.02, we saw issues with new Teams and ODFC where some settings are not saved when the user signs out. New in 25.02 were changes to improve how these settings are captured prior to user sign out.

FRXShell rule fails clean up and prevents all user sign ins

Description: Under some situations, the FRXShell rule would apply to all users preventing sign in.

Cause: Due to the issue, "FSLogix Rules do not apply to users as expected", we fail to assign the FRXShell rule. Without the assignment, our cleanup task would not remove the rule and resulted in the FRXShell rule applying to all users.

After signing in, user receives an error message that the Recycle Bin is corrupted

Description: Users would intermittently receive a notification after signing in that the "Recycle Bin is corrupted".

Cause: We discovered an issue where users were unable to access the Recycle Bin within their profile VHD.

Searchindexer.exe (frx_usermode_x64.dll) crashing in Windows Server 2016

Description: Searchindexer.exe would crash on systems running Windows Server 2016.

Cause: We identified an issue where we implement functionality for Windows Search and Outlook Cached Mode. An updated call to these components would cause the Searchindexer.exe to crash.

FSLogix v3 Release 25.02 is now generally available!

Jason_Parker — Wed, 12 Feb 2025 03:58:43 GMT

Another long journey getting version 3 out to the public. We've been testing this version in our Early Access program since November 2024. Huge thank you to all the contributors for their feedback and validation.

FSLogix Release Notes - FSLogix | Microsoft Learn

What's new

Major version change (2 → 3) and updated how FSLogix release names and build versions are defined. In future releases, major releases will increment the major version from 3 to 4 to 5, etc.
- Example:
  - Release name: 25.02
  - Build version: 3.25.202.4223 (3.YY.MMDD.HHMMS, Single digit months will not have a leading 0)
Cloud Cache no longer assumes some failure states are a bad configuration and will now allow customers to test and validate their configurations for redundancy through any method they choose.
Microsoft.FSLogix PowerShell module used for Cloud Cache investigation and troubleshooting.
When RedirXMLSourceFolder is removed or 'not configured' in Group Policy, the redirections.xml file is now removed from within the user's profile container at the next sign-in.

Fixed issues

LocalCache and TempState folders for MSIX packages are now properly cleaned up during sign-out.
Fixed an issue related to symlink reparse points affecting App-V and other components that have similar calls.
VHD disk compaction for differencing disks now works the same as disks without a differencing disk.
- Note: Compaction results will still be based on each disk and what space is able to be reclaimed during the optimization.
ADMX templates have been updated to allow settings that are enabled by default to be disabled.
Sign-in and sign-out optimizations to ensure MSIX settings are properly handled before and after the Windows shell events.

Feature retirement

Support for Windows Server 2012 R2
Support for 32-bit operating systems
Cloud Cache CcdMaxCacheSizeInMBs (limited cache)
Profiles Configuration Tool
App Container Rules
Internet Explorer browser plug-in
Application Rule Set license reporting
Java Rule Editor and Java Rules
FRXTray utility

FSLogix v3 Release 25.XX is now in Early Access!

Jason_Parker — Thu, 05 Dec 2024 18:21:55 GMT

It has been quite some time (about two years) since we released a new version of FSLogix that wasn't just a hotfix. This delay led many to wonder if the product was abandoned or no longer under development. Although it took longer than expected to release this version, we prioritized aligning our product's functionality with other Microsoft products that our customers rely on, such as Microsoft Teams.

While this version may not be packed with numerous flashy new features, we have made significant updates and improvements to enhance overall stability. With this release, we are committed to continued investment in our early access program, ensuring that our members can always be at the forefront as we plan for future updates.

Joining the early access program is easy but requires an existing NDA:

~~Sign up for an NDA with Microsoft~~
Register to join the Microsoft Management Customer Connection Program (https://aka.ms/joinccp)
- Submitting a request to join the MM CCP will validate if you have an existing NDA.
- If you don't have an NDA, you will need to work with your Microsoft representative to sponsor your NDA.

Release Notes

These release notes are considered to be in draft until the general availability release and are subject to change.

What's New

Major version change (2 → 3) and updated how FSLogix release names and build versions are defined. In future releases, major releases will increment the major version from 3 to 4 to 5, etc.
- Example
  - Release name: 25.02
  - Build version: 3.25.211.8452 (3.YY.MMDD.HHMMS)
Cloud Cache no longer assumes some failure states are a bad configuration and will now allow customers to test and validate their configurations for redundancy through any method they choose.
Microsoft.FSLogix PowerShell module used for Cloud Cache investigation and troubleshooting.
When unconfigured, redirections.xml is now removed from the user's profile container.

Fixed issues

LocalCache and TempState folders for MSIX packages are now properly cleaned up during sign-out.
VHD disk compaction for differencing disks now works the same as disks without a differencing disk.
- NOTE: Compaction results will still be based on each disk and what space is able to be reclaimed during the optimization.
ADMX templates have been updated to allow settings that are enabled by default to be disabled.
Sign-in and sign-out optimizations to ensure MSIX settings are properly handled before and after the Windows shell events.

NOTE: This is most notable when reviewing text logs

===== Begin Session: Post Profiles Logon
===== End Session: Post Profiles Logon
===== Begin Session: Pre Profiles Logoff
===== End Session: Pre Profiles Logoff

Feature retirements

No support for Windows 7 or Server 2012 R2
No support for 32-bit versions of Windows
Limited cache for Cloud Cache (aka CcdMaxCacheSizeInMBs)
Profile configuration tool
VHD application containers
Browser plug-in
App Rule Set license reporting
Java Rule Set Editor
frxtray.exe

FSLogix is now part of the Microsoft Management Customer Connection Program (MM CCP)!

Jason_Parker — Wed, 04 Jun 2025 16:13:57 GMT

FSLogix is a complex tool that is used in a wide range of environments. Testing and validating these environments is extremely challenging as an engineering team and we rely on customers like you to help us test, validate and ensure our product is meeting the needs of all our customers.

FSLogix is partnering with the Microsoft Management Customer Connection Program (MM CCP) to provide customers and professionals with a forum to join exclusive conversations, feedback and access to future versions of the product. FSLogix is part of the Windows Cloud Experience (WCX) organization where you can find AVD, Windows 365, and the new 'FSLogix and user profile discussion' channels.

Join the MM CCP today!

https://aka.ms/JoinCCP

MM CCP is a mutually beneficial program where members have engagement opportunities and access to member exclusive information and other benefits with participating MM CCP Communities like:

Data Security and Privacy Customer Connection Program
Microsoft Purview products: Information Protection, Data Loss Prevention, Insider Risk Management, Microsoft Purview Data Governance, eDiscovery, Audit, Data Lifecycle Management, Records Management and Microsoft Priva 
Security Connection Program
SIEM & XDR, CNAPP (Defender for Cloud), & Network Security
Management Customer Connection Program
Microsoft Intune product family, Windows and Windows Cloud Experiences (WCX)
Microsoft Entra Advisors 
Microsoft Entra Permissions Management, Microsoft Verified ID, Identity Advisors, Identity Developer Advisors, Identity in Education, Azure B2C Advisors 
Copilot for Security Customer Connection Program

Participation in MCCP is voluntary. To opt-out of MCCP at any time, visit: https://aka.ms/CCPOptOut

Announcing general availability for FSLogix 2210 hotfix 4!

Jason_Parker — Tue, 14 May 2024 19:13:39 GMT

FSLogix 2210 hotfix 4

This hotfix, along with the updates from hotfix 3, address a wide range of issues associated with the new Microsoft Teams. We wish to express our gratitude to the 30+ customers and partners whose crucial involvement in our validation process has been essential for the discoveries and solutions provided in this release. Additionally, we are reintroducing a previously released and highly requested feature: Asynchronous Group Policy processing!

What's new

Group Policy processing can now occur asynchronously for users during sign-in.
MSIX folders under %LocalAppData%\Packages\<package-name>\ will automatically get created when an ODFC container is created (new or reset container).
New Microsoft Teams data located in %LocalAppData%\Publishers\8wekyb3d8bbwe\TeamsSharedConfig will now roam with the ODFC container.

Fixed issues

Windows Server 2019 would sometimes fail to query the provisioned AppX applications for the user during sign-out.
MSIX folders that should not be backed up, would be removed during sign-out instead of only removing the contents of those folders.
New Microsoft Teams crashes or fails to start in Windows Server 2019.
New Microsoft Teams would display an error during launch with The parameter is incorrect.
New Microsoft Teams would display an error during launch with Invalid function.
New Microsoft Teams would not on-demand register during sign-in when using the ODFC container.
New Microsoft Teams would not on-demand register during profile creation and would not register during future sign-ins, despite being installed.
User-based Group Policy settings would persist in the user's profile after the policy setting was removed or set to disabled.

Release Notes | FSLogix 2210 hotfix 4

Announcing general availability of FSLogix 2210 hotfix 3!

Jason_Parker — Wed, 13 Mar 2024 20:14:29 GMT

We are pleased to announce the general availability of FSLogix 2210 hotfix 3 (2.9.8784.63912).

Important News!

We recognize many customers are under pressure to deploy new Teams in anticipation of the upcoming June 30, 2024 deprecation of classic Teams. We have released this version "out of band" of our expected integration in the Azure marketplace images in order to expedite the adoption process. This version will be pre-installed in the Azure marketplace images on ~~March 12th, 2024~~. We had to slip the date for the marketplace images. We will plan a new blog post when HF4 nears GA.

What's new in FSLogix 2210 hotfix 3?

This hotfix release specifically enables compatibility and support for the new version of Microsoft Teams which became generally available on December 5th, 2023. Following our preview release of hotfix 3, we found some minor changes needed for the behavior when using profiles and ODFC or ODFC only. We have an outstanding bug for Windows Server 2019, and it continues to be one of our top priorities.

Most notable changes in hotfix 3 are in how we register the new Teams AppX package (by family name) and persisting the user data located in: %LocalAppData%\Packages\MSTeams_8wekyb3d8bbwe\LocalCache.

A handful of customers have seen unexpected reboots due a bugcheck (various stop codes) due to redirects getting cleaned up for active sessions. This was also included in the hotfix 3 release.

Documentation updates:

Announcing general availability of FSLogix 2210 hotfix 2!

Jason_Parker — Tue, 22 Aug 2023 18:45:28 GMT

We are pleased to announce the general availability of FSLogix 2210 hotfix 2 (2.9.8612.60056).

Important News!

Following our last blog post, we encountered a last-minute process change. FSLogix 2210 hotfix 2 can be found in the Azure Marketplace images of Windows multi-session that also include Microsoft 365 apps. Images without Microsoft 365 apps have 2210 hotfix 1 (2.9.8440.42104) pre-installed. In the upcoming September 12th, 2023 update of the Azure Marketplace images, all images will have 2210 hotfix 2 (2.9.8612.60056) pre-installed.

What's new in FSLogix 2210 hotfix 2?

This hotfix provides major bugfixes to the Cloud Cache components of FSLogix where customers have seen issues with timed write cache and other I/O processing behaviors. Through our early access customers and customers who've opened support cases, we have been able to confirm that many of these issues have been resolved. Thank you!

A handful of customers have seen unexpected reboots due a bugcheck (various stop codes) and issues with ODFC containers which did not detach correctly. Both of these issues were also addressed.

Lastly, this hotfix provides significant changes to our Group Policy template files, which will NOT affect their functionality and are focused on aesthetics and compatibility.

To learn more about this release, please visit the FSLogix release notes.

FSLogix feature deprecation

As part of this release, we are also announcing some features which we plan to retire in March 2024. Coming to these decisions was not easy, but they were made with the following in mind:

Supportability and end of life
UX design issues
Broken functionality causing customer confusion or misunderstanding

Announcing FSLogix release changes and Windows multi-session updates in Azure Marketplace

Jason_Parker — Tue, 15 Aug 2023 15:30:04 GMT

Announcement: FSLogix release changes and Windows multi-session updates in Azure Marketplace

Tired of checking and installing FSLogix after deploying your Session Hosts with a Windows multi-session image from the Azure Marketplace?

As of August 8th, 2023 (patch Tuesday), these images will come with the latest version of FSLogix already installed. This means that you can skip the hassle of installing or updating FSLogix on your virtual machines and enjoy it's amazing features right away.

This updates the installed version in the Azure Marketplace images to FSLogix 2210 hotfix 1 (2.9.8440.42104) from FSLogix 2201 hotfix 1 (2.9.8171.14983).

FSLogix is a set of solutions that enhance, enable, and simplify non-persistent Windows computing environments. It improves the performance, scalability, and user experience of virtual desktops and applications. Some of the features of FSLogix include:

Roam user data between remote computing session hosts.
Minimize sign in times for virtual desktop environments.
Optimize file I/O between host/client and remote profile store.
Provide a local profile experience, eliminating the need for roaming profiles.
Simplify the management of applications and 'Gold Images'

FSLogix is now in sync with Windows and the “patch Tuesday” release schedule. This means that whenever there is a new version of FSLogix, it will be released on the same day as Windows updates and the Azure Marketplace images for Windows multi-session will always have the newest version of FSLogix from now on.

This is great news for anyone who wants to use Windows multi-session in Azure. You can save time and trouble by using the latest version of FSLogix in your virtual machines. If you want to learn more about FSLogix, you can check out our documentation. If you want to try out the Windows multi-session images with FSLogix in Azure, simply select an image from the Marketplace during your virtual machine creation.

Announcing general availability of FSLogix 2210 hotfix 1!

Jason_Parker — Fri, 03 Mar 2023 18:51:26 GMT

We are pleased to announce the general availability of FSLogix 2210 hotfix 1 (2.9.8440.42104). Huge thank you to the community of customers who have opted into our Early Release Preview list. These testers helped to ensure the fixes listed in our known issues page were resolved.

What's new in FSLogix 2210 hotfix 1?

During the release of 2210 GA, our team posted in the known issues page the significant change to how we were addressing identity roaming. We quickly heard from the community and our customers that this was a big problem. We quickly partnered with our identity team and created a configuration setting to re-enable this roaming behavior while a more long-term approach is evaluated.

Additionally, three (3) other issues which were not discovered in our previews became hot topics on social media and through our support channels. We've confirmed these issues are resolved and added a variety of other fixes.

To learn more about this release, please visit the FSLogix release notes.

Want to join the FSLogix Early Release Preview(s)?

FSLogix profile containers for Entra cloud only identities

Jason_Parker — Tue, 08 Apr 2025 21:36:14 GMT

Edited: April 8th, 2025

Over the past several weeks, the number of customers seeking this type of guidance has increased significantly. I am glad see that our customers continue to push the boundaries of our product and growing in their Azure based deployments of RDS, Azure Virtual Desktop, and other VDI solutions in Azure.

FSLogix does support non-traditional configurations for Entra only scenarios. ~~We are working to add this to our public documentation, however due to the number of instances where I've been asked about these configurations, a blog post was more immediate.~~ Customers who have Azure AD cloud only identities can use FSLogix in one ~~of two~~ configurations. This will be the only method available until Azure Files natively support Entra only identities.

Cloud Cache using Azure Page Blob storage account(s)

First, read this article on how to secure the Storage keys. The document is planned for an update, but the concept is sound. Next, review the list of recommendations below, before implementing this solution.

NOTE: These are recommendations for an optimal experience.

Do not use standard tier storage for Azure page blobs for production workloads.
Ensure the Azure page blob storage account is in the same region as the virtual machine(s) for optimal performance.
The Azure page blob storage account should use zone-redundant storage (ZRS) if available. If not available, use two (2) unique Azure page blob storage accounts using local-redundant storage (LRS)
Ensure the OS volume allocation size matches Azure page blob and the container (VHDx).
The virtual machine(s) should have high performaning local OS disks as Cloud Cache will create a local VHD for each profile as the source while keeping the blob versions up to date. Alternatively, the virtual machine could have a high-performance temp or data disk.
Typical Azure based deployments recommend 1 user per 1 vCPU. Using Cloud Cache, you should start with 1 user per 2 vCPU and closely monitor CPU and disk I/O. Continue to increase user load on the virtual machine(s) to find the right mix for your workload.
Do not use the CcdMaxCacheSizeInMBs setting.
Do not use ProfileType 1, 2, or 3.
Read all the Cloud Cache configuration settings on our public documentation page.

$fslBlob1ConnectString = (Get-AzStorageAccount -ResourceGroupName CONTOSO -Name fslstgacct001premblob).Context.ConnectionString $fslBlob2ConnectString = (Get-AzStorageAccount -ResourceGroupName CONTOSO -Name fslstgacct002premblob).Context.ConnectionString & "C:\Program Files\FSLogix\Apps\frx.exe" add-secure-key -key fslstgacct001-CS1 -value $fslBlob1ConnectString & "C:\Program Files\FSLogix\Apps\frx.exe" add-secure-key -key fslstgacct002-CS1 -value $fslBlob2ConnectString New-ItemProperty -Path HKLM:\SOFTWARE\FSLogix\Profiles\ -Name CCDLocations -PropertyType multistring -Value ('type=azure,name="AZURE PROVIDER 1",connectionString="|fslogix/fslstgacct001-CS1|";type=azure,name="AZURE PROVIDER 2",connectionString="|fslogix/fslstgacct002-CS1|"') -Force

Alternate options:

Removed previous alternate options as one had a broken link and the other no longer worked and we were unable to get the solution to work successfully.

Announcing general availability of FSLogix 2210

Jason_Parker — Wed, 14 Dec 2022 00:37:17 GMT

We are pleased to announce the general availability of FSLogix 2210. This latest version is focused on three core features, six bug fixes, and two general updates. We've added several new articles to our documentation and updated the configuration settings reference page.

What's new in FSLogix 2210?

FSLogix added three new features. First, VHD Disk Compaction, which allows the user's container to shrink during the sign-out phase. VHD Disk Compaction will reduce the amount of consumed storage for user's profile. Second, we've added a new process during the sign-out phase which creates an AppX package manifest for the user. This manifest is used at sign-in to re-register the AppX applications for an improved user experience. Lastly, when users delete data from within their session, we now roam the user's Recycle Bin which allows them to restore it from another session.

It's important to note that users may be required to authenticate to their applications (e.g., Microsoft 365 apps, Teams (work or school), OneDrive, etc.) at every sign-in. Check out the known issues page for more information.

To learn more about this release, please visit the FSLogix release notes.

FSLogix Customer Experience Survey is live!

Jason_Parker — Thu, 04 Aug 2022 22:05:24 GMT

All...

I am pleased to announce our Customer Experience Survey is now live!

FSLogix is looking for feedback from our customers and community to help shape the current and future iterations of the product. FSLogix is widely used across Azure Virtual Desktop, Azure, and On-Premises deployments and we want to ensure we continue to deliver fixes, enhancements and features that are meaningful across these segments.

Thank you and we look forward to your responses!

Using custom names for folders and containers

Gonzalo_Reyna — Fri, 29 Jul 2022 18:28:41 GMT

FSLogix creates containers and folders using a default naming convention. Folders are created using the default value %sid%_%username% and can be customized by modifying registry setting SIDDirNamePattern or GPO setting “SID directory name pattern string”. For the containers name, the default value is Profile_%username% for Profile container and ODFC_%username% for Office container and can be customized by modifying registry setting VHDNamePattern or GPO setting “VHD name pattern string”.

Here in the support team, we have seen many cases where configuring these two values will cause an odd issue: your FSLogix container is loaded the first time, but consecutive times it is not loaded. To understand why this issue occurs, we will need to look in depth at the different values that are used when the profile is created and when it is loaded.

Every time a user logs in, we will always verify if a container exists using the following parameters to determine where to look and what to look for:

VHDLocations or CCDLocations.
SIDDirNameMatch
VHDNameMatch
VolumeType

This means that we will search for an existing container here: VHDLocations\SIDDirNameMatch\VHDNameMatch.VolumeType

If the profile does not exist, then we will create a new container using the following parameters:

VHDLocations or CCDLocations.
SIDDirNamePattern
VHDNamePattern
VolumeType

Putting the values together will result in creating the container here VHDLocations\SIDDirNamePattern\VHDNamePattern.VolumeType

In paper this looks easy to follow and you might be wondering where the problem is and why dedicate a blog to talk about this. Well, the problem is that, many times, when you want to customize either the directory or container naming convention, most of the times only SIDDirNamePattern and VHDNamePattern are modified resulting in an undesirable situation.

To better understand this, we will use the following configuration values:

VHDLocations: \\sample.file.core.windows.net\fslogix
SIDDirNameMatch: Default - %sid%_%username%
SIDDirNamePattern: Custom - %username%.%userdomain%
VHDNameMatch: Default - Profile*
VHDNamePattern: Custom - %username%
VolumeType: Default – vhd
Username: testuser
Domain dev
SID: SID S-1-5-21-2345234234-2346554-8794543-1710

Let’s review what would happen during the first two logons for a new user:

User logs in for the first time and, as we previously explained, we check for an existing profile using the following parameters: VHDLocations\SIDDirNameMatch\VHDNameMatch.VolumeType. Using the given values, we will be checking for an existing file that matches this: \\sample.file.core.windows.net\fslogix\S-1-5-21-2345234234-2346554-8794543-1710_testuser\Profile*.vhd.
Since this is the first time that the user login (we know that) and the profile container does not exist, we will create a new container using the following parameters: VHDLocations\SIDDirNamePattern\VHDNamePattern.VolumeType. With the provided values, we will create our container here: \\sample.file.core.windows.net\fslogix\testuser.dev\testuser.vhd.

At this point the user testuser has a new profile container created and we will expect that the next time it logs in, his new profile is loaded. Let’s review what happens during the second login:

User logs in for the second time and, as I mentioned before, we will always look for an existing profile first, so we will check for an existing profile here: \\sample.file.core.windows.net\fslogix\S-1-5-21-2345234234-2346554-8794543-1710_testuser\Profile*.vhd. The result for this first operation is “File does not exist”, so we proceed to create a new profile, but then the creation of the new profile fails with error “File already exist”.

How could this be possible if the user was able to login successfully and create its profile but the subsequent times it is erroring with “File already exist”? Perhaps you already spotted the cause, and I am glad that you did it. If not, keep reading.

The reason for the error is because you are using two different locations based on the settings you have:

When creating a profile	VHDLocations\SIDDirNamePattern\VHDNamePattern.VolumeType	\\sample.file.core.windows.net\fslogix\testuser.dev\testuser.vhd.
When looking for a profile	VHDLocations\SIDDirNameMatch\VHDNameMatch.VolumeType	\\sample.file.core.windows.net\fslogix\S-1-5-21-2345234234-2346554-8794543-1710_testuser\Profile*.vhd

You will notice that the path is different since one of them does not have the SID. But there is also, there is another difference, and it is in the filename, because we are looking for any file that has “Profile” at the beginning of the name. Let’s look at FSLogix Profile log for this entire process and see what we find.

Every time we have a user login, we will log current values. Here is the section of interest

[21:02:09.727][tid:00000dd0.00001c0c][INFO] Configuration setting not found: SOFTWARE\FSLogix\Profiles\SIDDirNameMatch. Using default: %sid%_%username%

[21:02:09.727][tid:00000dd0.00001c0c][INFO] Configuration setting not found: SOFTWARE\FSLogix\Profiles\VHDNameMatch. Using default: Profile*

[21:02:09.727][tid:00000dd0.00001c0c][INFO] Configuration setting not found: SOFTWARE\FSLogix\Profiles\VolumeType. Using default: vhd

[21:02:09.743][tid:00000dd0.00001c0c][INFO] FindFile returning after 16 milliseconds

[21:02:09.743][tid:00000dd0.00001c0c][INFO] Configuration Read (REG_SZ): SOFTWARE\FSLogix\Profiles\SIDDirNamePattern. Data: %username%.%userdomain%

[21:02:09.743][tid:00000dd0.00001c0c][INFO] Configuration Read (REG_SZ): SOFTWARE\FSLogix\Profiles\VHDNamePattern. Data: %username%

We will search for the file, but since this has not been found, we will create a new one.

[21:02:09.743][tid:00000dd0.00001c0c][INFO] Profile VHD not found. Creating new VHD.

[21:02:09.759][tid:00000dd0.00001c0c][INFO] ===== Begin Session: Create Formatted Disk

[21:02:09.837][tid:00000dd0.00001c0c][INFO] Created vhd(x): \\sample.file.core.windows.net\fslogix\testuser.dev\testuser.vhd

During the second logon, we will check again if the disk exists and, because the file does not exist, we will create a new container, but it will fail with error "The File Exist".

[21:11:41.874][tid:00000dd0.00001da8][INFO] Profile VHD not found. Creating new VHD.

[21:11:41.890][tid:00000dd0.00001da8][INFO] ===== Begin Session: Create Formatted Disk

[21:11:41.890][tid:00000dd0.00001da8][ERROR:00000050] VirtualDiskAPI::CreateFormattedDisk failed to create vhd(x): \\sample.file.core.windows.net\fslogix\testuser.dev\testuser.vhd (The file exists.)

How can we fix this issue? We need to understand that the values used for folder and file naming convention work in pairs, this means that, if you modify SIDDirNamePattern, you need to make sure that you set the same value for SIDDirNameMatch. If you change the value for VHDNamePattern, you need to make sure that you set either the same value for VHDNameMatch or a value that will help to find the right disk. In our scenario, the values should be changed as follows:

Before

After

SIDDirNameMatch: Default - %sid%_%username%

SIDDirNamePattern: %username%.%userdomain%

VHDNameMatch: Default - Profile*

VHDNamePattern: %username%

SIDDirNameMatch: %username%.%userdomain%

SIDDirNamePattern: %username%.%userdomain%

VHDNameMatch: %username%

VHDNamePattern: %username%

You might be wondering: Gonzalo, can you please clarify what you mean by “you need to make sure that you set either the same value for VHDNameMatch or a value that will help to find the right disk.”? To answer this question, let’s take a look at the default values for VHDNameMatch and VHDNamePattern. Default value for VHDNamePattern is “Profile_%username%” and for VHDNameMatch is “Profile*”. You will notice that it has an “*” at the end. By using a wildcard we are looking for any file that starts with “Profile_”. If you for example decide to modify VHDNamePattern value to “Profile_%username%.%profileversion%”, the value in VHDNameMatch will still work because both of them start with “Profile_”

I really hope that this blog helps you to have a better understanding about how to customize your FSLogix deployment.

FSLogix 2201 hotfix 2 (2.9.8228.50276) has been released!

Gonzalo_Reyna — Thu, 21 Jul 2022 22:07:16 GMT

Hello FSLogix nation,

We got some exciting news today from Jason_Parker about the release of FSLogix 2201 hotfix 2.

FSLogix Release Notes - FSLogix | Microsoft Docs

Summary

This update for FSLogix 2201 includes fixes to multi-session VHD mounting, Cloud Cache meta tracking files, and registry cleanup operations.

Changes

Resolved an issue that would cause a system crash while reading from meta tracking files in a Cloud Cache configuration.
Resolved an issue where a logon would succeed even if when the disk failed to attach. Most commonly occurs in multi-session environments.
Resolved an issue during profile cleanup where user registry hives would be removed regardless of the FSLogix local group exclusions.

File Information

Download the following package and follow the installation instructions

Download FSLogix 2201 hotfix 2 (2.9.8228.50672)

FSLogix and APP-V

Philip_McLoughlin — Sun, 23 Mar 2025 12:36:39 GMT

Hello FSLogix Nation,

Phil here from the FSLogix and APP-V team.

I wanted to share the following with you after we had a few customers contact Microsoft when using FSLogix and APP-V.

If you are using APP-V with FSLogix then you may have encountered some issues when launching APP-V applications.

You also may have encountered White Icons being displayed on the desktop or Start Menu.

You may also want to ensure that you roam the COW to every machine on logon for a number of APP-V applications.

Well to address the above you need to ensure that you have a FSLogix Redirections.xml configured with the following entries:

<?xml version="1.0" encoding="UTF-8"?>

<Exclude Copy="0">AppData\Local\Microsoft\Appv\Client</Exclude>

</Excludes>

<Include>AppData\Local\Microsoft\AppV\Client\VFS</Include>

</Includes>

</FrxProfileFolderRedirection

Remember: When we use an exclude we may want to use an include of the subfolder whose parent folder we are excluding

Includes are only necessary when the folder is in the exclude folder or further down the path of the exclude folder.

Also as the Integration points get broken on logoff with FSlogix (as we remove the whole users profile), you should also have this APP-V setting configured:

PreserveUserIntegrationsOnLogin

Configure in the Registry under HKEY_LOCAL_MACHINE \ Software \ Microsoft \ AppV \ Client \ Integration.
Create the DWORD value PreserveUserIntegrationsOnLogin with a value of 1.
Restart the App-V client service or restart the computer running the App-V Client.

Hope the above helps!

UPDATE 23.3.2025:

Please refer to this article for an update.

Announcing FSLogix 2201 hotfix 1 (2.9.8171.14983) has been released!

Gonzalo_Reyna — Thu, 26 May 2022 21:32:09 GMT

Hello FSLogix nation,

We got some exciting news today from Jason_Parker about the release of FSLogix 2201 hotfix 1.

FSLogix Release Notes - FSLogix | Microsoft Docs

Summary

This update for FSLogix 2201 includes fixes to Cloud Cache and container redirection processes. No new features are included with this update.

Changes

IMPORTANT

This is a **hotfix** for FSLogix 2201 (2.9.8111.53415). If you are using Cloud Cache or have experienced intermittent system crashes as a result of FSLogix, it is recommended to install this update.

Resolved an issue with Cloud Cache where disk read / write blocking could potentially create a deadlock to the disk and cause the Virtual Machine to become unresponsive.
Resolved an issue that would cause a Virtual Machine to crash while removing profile redirections during the sign out process.

File Information

Download the following package: Download FSLogix 2201 hotfix 1 (2.9.8171.14983)