I open SourceTree and try to clone a GitHub organization repository, for which I'm an admin of, through the "Clone" section of the desktop app, but every time I do that this error appears: "This is not a valid source path / URL". When I click "Details", this appears (note: "[URL]" is a substitute for the actual URL of the GitHub repository):
Command: git -c diff.mnemonicprefix=false -c core.quotepath=false --no-optional-locks ls-remote [URL]
Output:
Error: remote: Repository not found.
fatal: repository '[URL]' not found
Command: hg identify extensions.hgext.hgsubversion=! [URL]
Output:
Error: abort: HTTP Error 404: Not Found
Command: perl.exe C:\Users\andre\AppData\Local\Sourcetree\app-3.4.21\tools\svn.pl info [URL]
Output:
Error: System.ComponentModel.Win32Exception: Impossibile trovare il file specificato
This has never happened before, I always cloned the repository just fine. I have no idea how to proceed. I've seen too much confusing information online and none of it seems to help.
I managed to solve the issue in question by myself. I'm writing this information down in case anyone in the future stumbles upon this problem too.
What I had to do, inside SourceTree account settings, is authenticate my GitHub account not through "OAuth", as I did before, but using "Personal Access Token". The SourceTree app then asked me to login and put my PAT as a password. I generated my PAT through this link: https://github.com/settings/tokens. I checked all boxes while creating the token and made it so it never expires, despite GitHub suggesting me not to (note that I'm merely saying what I did in order to make it work for me; don't take this information as advice on what should be done in general under these circumstances).
Hope this is useful to anyone.