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FSLogix Release 25.06 is now generally available!

Jason_Parker's avatar
Jason_Parker
Icon for Microsoft rankMicrosoft
Jul 08, 2025

Introducing compatibility and support for Microsoft Outlook for Windows

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
Published Jul 08, 2025
Version 1.0

16 Comments

  • Mike_Zirbes's avatar
    Mike_Zirbes
    Copper Contributor
    Sep 08, 2025

    Running this on Server 2022 both v25.04 and v25.06 are generating a login error when a user attempts a second login. We are using cloud cache.

    I have researched the error and found no fix. I uninstalled FSlogix and tested with local profiles and users are able to login as many times as they need. This does not happen on our Win11 VDI nor our Server 2019 systems. Other event log errors include:

    Event 1508: 

    Windows was unable to load the registry. This problem is often caused by insufficient memory or insufficient security rights. 

     DETAIL - Access is denied.
     for C:\Users\<user>\ntuser.dat

    and

    Windows cannot load the locally stored profile. Possible causes of this error include insufficient security rights or a corrupt local profile. 

     DETAIL - Access is denied.

    Event 1509

    Windows was unable to load C:\Users\<user>.FSL0\ntuser.dat.

    Event 1502

    Windows cannot load the locally stored profile. Possible causes of this error include insufficient security rights or a corrupt local profile. 

     DETAIL - Access is denied.

    Event 6004

    Event 1552 User hive is loaded by another process (Registry Lock) Process name: C:\Windows\System32\svchost.exe, PID: 1264, ProfSvc PID: 2436.

  • Buffalo6768's avatar
    Buffalo6768
    Copper Contributor
    Aug 08, 2025

    After upgrading to FSLogix 25.06 in our VMware Horizon environment (Instant Clones, Windows 10/11, Hybrid Azure AD Join), all users must log in to Office 365 (Outlook, OneDrive, Teams) again each time they log in.

  • Mark_Blackwood's avatar
    Mark_Blackwood
    Copper Contributor
    Jul 16, 2025

    We are seeing the below error since the July CU was released, we upgraded FSLogix to this new version, but the error still occurs.
    We only see it on a device that has FSLogix installed.

    Has anyone else seen this? We have opened a case.
    Mark

    • CTaylorCoSM's avatar
      CTaylorCoSM
      Copper Contributor
      Aug 06, 2025

      We're getting this same error. Have you found a fix for it yet? We've not been able to pin down why this is happening. As far as I can tell it's due to to the VHDX disconnecting and not properly reattaching, but it's not super clear why that is happening.

    • Thomas_001's avatar
      Thomas_001
      Copper Contributor
      Jul 16, 2025

      Do you have the Phone Link app installed? if so perhaps try uninstalling it and see if the error goes away.

      • Mark_Blackwood's avatar
        Mark_Blackwood
        Copper Contributor
        Jul 21, 2025

        Nope we don't have the Phone Link app installed on our image.

        I did notice this new option available since the July patch

         

  • bgarver's avatar
    bgarver
    Copper Contributor
    Jul 11, 2025

    I am experiencing issues with the Rules Editor program. When installing the 25-06 version, the installation succeeds, but then when launching it, it will show "The code execution cannot proceed because zlib1.dll was not found. Reinstalling the program may fix this problem." I have made sure that both vc_redist x86 and x64 are installed. This issue occurs on multiple computers. 

    Version: 3.25.401.15305 works just fine installing and launching.

  • mzsolutions302's avatar
    mzsolutions302
    Copper Contributor
    Jul 10, 2025

    Great article.  So this fix provides compatibility for the MSIX version of Outlook.  

  • Jelle1905's avatar
    Jelle1905
    Copper Contributor
    Jul 09, 2025

    Hi,

    We are still waiting for an update regarding the known OneDrive issue. To work around the problem, we previously downgraded FSLogix. However, since Teams Legacy is no longer supported, we can no longer remain on the older FSLogix version and had to update.

    -On Windows Server 2019, OneDrive intermittently gets stuck at the "Signing in" stage.

     

     

    • jm090's avatar
      jm090
      Copper Contributor
      Jul 14, 2025

      I have this on Server 2025.. I can sign in once with a new profile, then it breaks after second sign in and have to delete the profile.

      • Vimal-Jobs's avatar
        Vimal-Jobs
        Copper Contributor
        Jul 17, 2025

        Could you please check on the corrupted VHD ( by mounting it ) if the NTUSER.Dat exists, if not then there could some other OS process deleting the profile even before FSlogix hives out the user registry/ NTUSER.dat

    • Sachin_Bhardwaj's avatar
      Sachin_Bhardwaj
      Copper Contributor
      Jul 14, 2025

      Jelle1905​ - 

      Could you please confirm whether the issue you're referring to also affects the latest version of FSLogix? I’m currently running FSLogix version 25.04 on Windows Server 2019, along with OneDrive version 25.075.0420.0002, and everything is functioning as expected.

      Has this issue been reported specifically with FSLogix version 25.06?

      • Jelle1905's avatar
        Jelle1905
        Copper Contributor
        Jul 14, 2025

        Sachin_Bhardwaj​ Thank you for the response, that would be interesting. For now we are running 25.04 in Windows server 2019 with the same OneDrive version. For the people that reported the problem this started on FSlogix 2210 hotfix 4. Back then downgrading would solve the problem, but Teams legacy client is no longer supported. You can read about it in the known isseus section: https://learn.microsoft.com/en-us/fslogix/troubleshooting-known-issues

  • MK_ultra's avatar
    MK_ultra
    Copper Contributor
    Jul 09, 2025

    Hi Jason,

    is there any update with this:

    • OneDrive is intermittently stuck at signing in on Windows Server 2019.

    When we can expect solution?

    Thanks in advance!