Important update available for Exchange Server 2013 hybrid deployments

Published Jul 30 2014 12:45 PM 42.2K Views

Update 8/26/14: changed the resolution to include the release of Exchange 2013 Cumulative Update 6 (CU6).

An important update is now available to resolve issues customers are currently experiencing when using the Hybrid Configuration Wizard (HCW) to create a new or manage an existing hybrid deployment with Microsoft Exchange Server 2013.

If you currently have an Exchange 2013-based hybrid deployment configured, you will not notice any issues unless you rerun the HCW as part of updating or managing your existing hybrid features. If you need to reconfigure your hybrid deployment, you should instll Exchange Server 2013 (Cumulative Update 6) to correct this issue with the HCW.

For Exchange 2013 organizations creating new or managing an existing hybrid configuration with the HCW, the following HCW error message indicates you are experiencing the issue this update addresses:

Subtask CheckPrereqs execution failed: Check Tenant Prerequisites Deserialization fails due to one SerializationException: Microsoft.Exchange.Compliance.Serialization.Formatters.BlockedTypeException: The type to be (de)serialized is not allowed: Microsoft.Exchange.Data.Directory.DirectoryBackendType

If you experience this issue, please install Exchange 2013 Cumulative Update 6 (CU6).

Brian Shiers
Technical Product Manager


Q: I’ve already configured a hybrid deployment with Exchange Server 2013 and I don’t need to make any changes to my hybrid configuration or features, do I need to apply this (interim) update?

A: No, you can wait for the fix to be delivered in the next Exchange Server 2013 update as long as you don’t have the need to run the Hybrid Configuration Wizard. EDIT: CU6 is now released and available.

Q. I may need to make updates to my Exchange 2013-based hybrid deployment before the next Exchange Server 2013 update, what are my options?

A. If you need to update your hybrid deployment features, install Exchange Server 2013 Cumulative Update 6 (CU6). Attempting to manually configure a new or update an existing hybrid deployment without HCW can result in unsupported hybrid deployment states.

Q: Are customers who use Exchange Server 2010 impacted by this update?

A: No, this only applies to customers using Exchange Server 2013 to configure a hybrid deployment with Office 365.

Q: If we apply the update specific for SP1 or CU5 do I have to do anything special to update to CU6 or later in the future?

A: The interim update does NOT need to be uninstalled. We allow later CU’s to install over Interim Updates and Security Updates directly as of CU3.

Not applicable
### BE AWARE ### Microsoft made a change to the Office 365 configuration that caused the Exchange 2013 Hybrid Configuration Wizard (HCW) to FAIL. No wonder why many do NOT want to go Hybrid.............
Not applicable
The instructions included with the interim update indicate it has to be uninstalled before CU6 is installed.

This conflicts with the above FAQ. Can you clarify this?

Not applicable
"The interim update does NOT need to be uninstalled. We allow later CU’s to install over Interim Updates and Security Updates directly as of CU3."

This is interesting. Just to confirm, since CU3 we're no longer required to uninstall Interim Updates before installing a new CU? That's very good news. Not that many customers have IU installed, but this statement caused a lot of misunderstandings in the past.

Not applicable
Not applicable
What services are affected here and is a reboot required?
Not applicable
thanks for sharing.
Not applicable
I'm having a very similar issue with a new Exchange 2013 install where I have an Exchange 2010 Hybrid already in place, this error appears during installation of 2013 SP1 when it recognises an existing Exchange Hybrid in place it asks, during install,

for my o365 credentials, after entering these, this error appears.

Not applicable
Hold times for support are becoming quite long. Promised call backs are not happening in a timely manner. Is there any way to obtain this IU without going through the long support process? Is this applied on-premise?
Not applicable
Thanks to this update, our Exchange is now broken.
Not applicable
The patch includes the note below. Can you clarify if uninstall will be needed or not when we go to CU6?

"*Note: This Interim Update package must be removed before installing any Exchange Server 2013 official rollup releases."

Not applicable
I have requested the Interim Update (IU) from MS 2 days ago and still waiting , does anyone now where I can download the Interim Update (IU) .
Not applicable
The fix requires a reboot of the Mailbox server. Why wasn't this issue fixed on the Cloud side instead of requiring customers to take down their systems?

The Fix, per Tier 3 support has also caused issues with clients servers, but there is no statement from Microsoft that the fix is eligible for free support in case of catastrophic failure of the Mailbox server after installation.

This is a direct quote from Tier 3 support regarding the fix "My sincere apologies, but we’re seeing some issues with the fix that was created to address this issue. We don’t want to risk breaking your existing environment. So, please stand by as we work to

resolve the issue(s) with the current fix. I will try update you as soon as possible."

Also if a customer does not have SP1 installed, they cannot use Office 365 hybrid, which directly contradicts the current 365 Hybrid documentation on Technet that states that the only CU needed for Hybrid configurations is CU1.

Not applicable
Has anyone successfully applied this? I installed on EX2013SP1CU5 and am no longer able to access ECP (or any other URL for that matter)

Not applicable
Has anyone got this hotfix yet?

i have 2 customers that are waiting for this and its not a good first impression of the service offered by Microsoft so far....

Not applicable
Support is clueless about this update. I have been on hold for 2 hours, meanwhile my client is suffering. Please fix this soon!
Not applicable
Thanks! I'll try and I'll tell you that the reboot is required.
Not applicable
Contacted MS and they would not give me the update and instead I was told I would need to wait for CU6. Not happy
Version history
Last update:
‎Jul 01 2019 04:19 PM
Updated by: