GitHub authentication no longer working

[nwbowensby]

I am an avid Sourcetree user and have been using it for years.  A few months ago I set up a colleague on it who had never used it before.  Our repository is on GitHub and works fine for me and did for them at first.  They were on other projects and came back to it and now they cannot push to the repository anymore due to an authentication issue.  The message implies they are trying to use a password which is no longer supported on GitHub.  I tried to help them out and I removed their current authentication and re-did it as OAuth and Sourcetree says it authentications successfully when you add it.  When you go to push you get the same authentication issue though.  Does anyone have any other thoughts?  Is it possible there is another place the authentication is being stored for the base git calls that might be interfering?

[Barnabás Nagy]

I have the same issue with bot GitHub and Bitbucket, actually. Changed my Atlassian password recently and I can't push changes now. I tried removing the account from Sourcetree and removing access on Bitbucket, completely redoing OAuth but it still won't work. I have the latest version of git and Sourcetree.

git -c diff.mnemonicprefix=false -c core.quotepath=false --no-optional-locks push -v --tags origin master:master
remote: Invalid username or password
fatal: Authentication failed for 'https://bitbucket.org/[…].git/'
Pushing to https://bitbucket.org/[…].git

Completed with errors, see above.