An attempt to communicate with Azure DevOps failed because a token could not be retrieved

You may try the following items:

1. Go to Control Panel -- Credential Manager, and remove all Windows Credentials related to TFS.
2. Close all Visual Studio instances, delete %LOCALAPPDATA%.IdentityService if it exists.
3. Clear TFS caches %LOCALAPPDATA%\Microsoft\Team Foundation\x.0\Cache
4. As @4c74356b41 mentioned, repair VS.