Process:

The only thing that worked for me was navigating to C:\Users\USERNAME\AppData\Local\Atlassian\SourceTree and removing the passwd file.

1. If you choose to remember password,, you need to remove password file:
   https://community.atlassian.com/t5/Sourcetree-questions/How-to-update-HTTP-S-credentials-in-sourcetree/qaq-p/297564