Unable to deactivate other users

Hello,
We bought 15 seats of Dorico 5 pro for our team. However, there are some members that we would like to deactivate their Dorico, but it says “This operation is currently not available”. What should we do as we want to give the other seats to other person.

Welcome to the forum, @incmusic.composition. Sorry that you’re having this problem! Are you able to deactivate those seats via the self-service portal here?