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
Exchange 2013 CU23
Windows Server 2012 R2
I installed the August 2022 update and enabled Extended Protection. Script went through without problems.
My problem now is, that some (not all users) get constant password prompts in Outlook 2016. Their Outlook can't login, putting in the password doesn't do anything, same prompt again. However, they can login to Outlook Web Access. Others have no problem at all. Everyone here has same Windows, same Outlook.
Can anyone help, any advice?
Update 08/22/2022:
I finally found the problem. On the clients, that get constant PW prompts when opening Outlook, check registry:
HKLM\SYSTEM\CurrentControlSet\Control\Lsa
The key "LmCompatibilityLevel" had value 1. On my PC (no problems with Outlook) the Key doesn't exist. So you can either delete the key or set its value to at least 3, restart the PC and Outlook should be working properly again.
Check the documentation here (see Method 1):
https://docs.microsoft.com/en-gb/troubleshoot/windows-server/remote/0xc000035b-when-you-use-lmcompatibility
If you have the same problem, you should find error 0xC000035B in your Exchange event viewer ("An account failed to log on").