Today I tried to connect to my Azure DevOps Account via Visual Studio to push some changed data of a project to git. First I got the error „Git failed with a fatal error. Authentication failed„. In my case the solution was to delete an entry in the windows credential manager. Read here how to open it. Just open the tab Windows Credentials and search for an entry looking like git:<yourdevopsservername>. Then you can delete it!
Afterwords I tried to open Visual Studio again to push my data to git. I got an error again saying „could not read username for visual studio terminal prompts disabled„. The solution for this case was to delete the file %localAppData%\GitCredentialManager\tenant.cache.
Hope this two steps will help someone to not spend more than one hour on solving the problem like me 😉