I am having issues trying to log on using OAuth
I did have 1.8 installed but uninstalled it to upgrade.
I am using Google Chrome Version 81.0.4044.92 (Official Build) (64-bit)
I am currently trying with 2.6.10 as it lets me install it (3.3.8 has OAuth during install does not work so can complete install)
After installing 2.6.10 it does not show any of my remote repo's. When adding an account via OAuth I click "Refresh OAuth token" and the page opened and I select my account then says "Authentication Successful, SourceTree has been successfully authenticated. You may now close this page."
But in the "Edit Hosting Account" screen it says "Login failed, Resource removed"

I have tried removing all cookies, all chrome extensions and/or using OAuth in a guest window, no difference.
in Chrome, before I was able to get this far, I would just keep getting a blank screen and I would keep seeing this error in the console.
"google:1 Uncaught TypeError: page.googleAuthCallback is not a function"
To log onto this forum I kept seeing this above error but when I took the offending line of code and copy/pasted it into the Chrome console to run it again I was able to log on.