The application you have selected does not exist

Hey all,

I tried to reactivate an app I purchased in the future that go updated (Serial Mailer 8).

The moment I tried I got the error "The application you have selected does not exist".

Since then I can't log in to any iCloud Apple ID related thing at all... (App Store, iMessage, etc...)

I tried to change my password a few times, I still get the same error.

Thanks in advance!

Tjark