Outside collaborators see an error when clicking on the invitation link, but the repository itself is created and available via link

[sseezov]

Everything worked fine until the new year, but recently, when outside collaborators clicked the invite link, they started seeing an access error screen ("Repository access issue. You no longer have access to your assignment repository. Contact your teacher for support"). However, their fork is created in the classroom, and they can access fork via the link and make commits. All their repositories are private.

[sseezov]

After clicking invite link they usually receiving email with invite to collaborate to classroom, and if they accept it everything works fine as before. But it was very convenient when the access screen opened immediately after creating a repository, because they still have full access to the fork.

[djmandell]

I can confirm this behavior, and the approximate time that it broke. It worked prior to the start of our winter break and stopped working some time after we came back from break.

As described above: when a student clicks "Accept Invitation" they see "Repository access issue." error. An email is generated, sent to the person, who can accept the invitation from the email and then get access to their repository. This makes a relatively painless process more painful, and because I'm dealing with high school students it can be a real hassle to work through.

[ethol]

Seems it's a more general problem with GitHub Classroom itself.
https://github.com/orgs/community/discussions/185262