Access denied message when attempting to Act As a colleague

Community Participant

Hi Canvas brains trust,

One of our teachers is experiencing a strange problem when they try to masquerade as a colleague. Perhaps someone can explain what's going wrong.

The two teachers have identical account admin permissions (I have checked this many times), but different course level enrolments. When teacher A tries to masquerade as teacher B, they get an Access Denied message at the point where they click "Proceed" to masquerade. Apparently it works fine the other way round.

Any insight - or even random guesses - would be most appreciated! 

Access Denied Screenshot