I'm not sure what happened but for some reason SourceTree choked on login the other day, and I ended up changing my Bitbucket password ultimately to see if that would fix it; now it can't log in even when I use that even though I can log into Bitbucket with it through the browser.
For the below screenshot, I went to (on my Mac) SourceTree menu > Preferences > Accounts > Add, which shows options Host: Bitbucket, Auth Type: OAuth, Username (No account connected), Protocol: SSH, SSH Key: id_rsa.pub.
I then clicked Connect Account, it popped up a box that seemed to connect to Atlassian's login screen through an embedded browser, it asked for my account email, I typed in the only email I use for Bitbucket and Atlassian, then the password, and then I get this odd invalid redirect and it says integration misconfigured:
I can log into either my Atlassian or Bitbucket account in the desktop browser just fine... no misconfiguration issue.
If I try SSH, it also fails authentication on Fetch or Pull even though those work totally fine on my Mac's command-line git in the repo directory.
I do have an SSH key set up with the command-line repo and Bitbucket, but I just cannot get anything to work suddenly in SourceTree now. I'm using version 2.7.6 (177).