Client can't access to his back-office anymore


I originally talked about this problem here:

The problem is related to Pro Sites. One client is a premium user (= not a free user). There was a problem about the monthly payment so his site's status became "expired pro site".

His subsite is using Domain Mapping and I set this a plugin as a Premium plugin (= for pro users only, not free users).

As a result, he couldn't connect to his back office and the result was the same when he tried with the subsite url ( or the mapped domain url ( For the mapped domain I think that makes sense, but I don't understand why he couldn't access to the back office of

Front-office remained OK though, on both and
But I guess it shouldn't work on, so it's a problem too.

Best Regards