Microsoft has released security updates (SUs) for vulnerabilities found in:
Exchange Server 2013
Exchange Server 2016
Exchange Server 2019
IMPORTANT: Updates are released in a self-extrac...
Updated Aug 11, 2022
Version 8.0
Blog Post
It started after installation of KB5008631. When going to in-place eDiscovery & hold in Exchange admin center, the list of searches failed to load and a message popped up with an error "Deserialization of type Microsoft.Exchange.Data.PropertyBag+ValuePair blocked due to NotInAllow at location MailboxDataStore."
Get-MailboxSearch in EMS would list the searches (all of them), then display:
WARNING: An unexpected error has occurred and a Watson dump is being generated: Deserialization of type
Microsoft.Exchange.Data.PropertyBag+ValuePair blocked due to NotInAllow at location MailboxDataStore.
Exception of type 'Microsoft.Exchange.Diagnostics.BlockedDeserializeTypeException' was thrown.
+ CategoryInfo : NotSpecified: (:) [Get-MailboxSearch], BlockedDeserializeTypeException
+ FullyQualifiedErrorId : Microsoft.Exchange.Diagnostics.BlockedDeserializeTypeException,Microsoft.Exchange.Manage
ment.Tasks.GetMailboxSearch
+ PSComputerName : ...
Support responded fairly quickly that "it's a known issue for KB5008631 and Microsoft has fixed this issue in next update". Then the fix was not included in the next SU. Then support revealed that it was marked for the next CU and the fix never came. I guess this particular support channel considers a case resolved once a bug is identified. So, they closed the case.
I've since upgraded the environment to Exchange 2019 and the problem went away. But it was frustrating to be told the issue was fixed, but that the fix was marked for a release that was never coming.
My case number was 29392575 if you want to look at the details. Maybe you can reassign the fix they were talking about from "next CU" to "next SU".