[Tip] Getting "fatal: Authentication failed for..." error
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[Win] C:\Users\USERNAME\AppData\Local\Atlassian\SourceTree 폴더의 passwd, userhosts 파일 삭제
[OSX] Home(Shift+Command+H)/Library/Application Support/SourceTree 폴더의 userid@STAuth-xxxxxx 파일 삭제
Library 안보이면 Home에서 Shift + Command + . (http://macnews.tistory.com/5286)
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The only thing that worked for me was navigating to C:\Users\USERNAME\AppData\Local\Atlassian\SourceTree and removing the passwd file.
Once this file is removed, restart SourceTree and execute a fetch or something else that requires access to the repo in question. SourceTree will then prompt you for your password, rewriting the cached credentials.
I hope this helps. Shoutout to my buddy Nick for the assist.
If you're a macOS user, Auke states below that "you can find the password files per repo it in ~/Library/Application Support/SourceTree"
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