There was an error accepting the assignment

I got an assignment to do on classroom.

When i accept the assignment i get the following message:

You accepted the assignment, assignment1 . We’re configuring your repository now. This may take a few minutes to complete. Refresh this page to see updates.

But when i refresh, I get this error:

There was an error accepting the assignment. We were not able to add the user to your assignment, please try again. If this problem persists, please contact support.