I was receiving an error regarding git lock file exists each time I pulled down in SourceTree, so I restarted SourceTree, now every subsequent Pull is returning "Authenticate" popup, and it not progressing with correct password.

This happened one other time, and after many retries it finally accepted the password. Appears to relate to issue SRCTREEWIN-3957.

Please advise, maybe server maintenance was occurring at this time. But I am currently blocked.

Thanks

UPDATE - FOUND BUG
On further investigation, see screenshot-1, it appears Xamarin or Visual Studio were locking the two folders in question which I believe caused the Authenticate popup to appear incorrectly. It seems if SourceTree detects a "permission denied" error (which is thrown by explorer) it determines it to be an authentication error.