Forum Discussion
After Exc 2019 Cu15 update Outlook problem
- Mar 17, 2025
Hello, our problem is solved.
It was enough to change the Network Security: LAN Manager authentication level setting to Send NTLMv2 response only.
The support matrix that you can use to validate:
https://learn.microsoft.com/en-us/exchange/plan-and-deploy/supportability-matrix?view=exchserver-2019
For password prompts there can be multiple scenarios, please have a look at those links to try to troubleshoot:
1. https://learn.microsoft.com/en-us/outlook/troubleshoot/authentication/continually-prompts-password-office-365
2. https://answers.microsoft.com/en-us/outlook_com/forum/all/microsoft-exchange-keep-asking-for-password/bda24332-a4b6-4267-bf5c-a83d4b095751
3. https://learn.microsoft.com/en-us/exchange/plan-and-deploy/install-cumulative-updates?view=exchserver-2019
4. https://learn.microsoft.com/en-us/exchange/error-message-when-upgrading-cumulative-updates?view=exchserver-2019
Hello, our problem is solved.
It was enough to change the Network Security: LAN Manager authentication level setting to Send NTLMv2 response only.