Today we are announcing the availability of the 2023 H1 Cumulative Update (CU) for Exchange Server 2019 (aka CU13). CU13 includes fixes for customer reported issues along with all previously released...
Updated May 09, 2023
Version 3.0
Blog Post
LukasSMSFT Thanks for the comment. I believe all the performance counters updated successfully, the logs indicate they all completed, it's right after that step where the error occurred. Yes, turned off Microsoft Defender realtime setting Set-MpPreference -DisableRealtimeMonitoring $true. I notice the antimalware service still uses CPU so I don't think the command does anything even though I also see the tic mark in the UI is off as well. Might be M365 Defender, can't turn that off. Or maybe sysmon gets in the way? Whatever the case, I had to reboot, manually stop all Exchange services and re-started the upgrade. It seems to have picked up where it left off and completed without further drama. This is the first time I have experienced an issue with a CU since the healthchecker was published.