Solution. not working universal license appstore:
Try to buy the universal license again in the App Store. Agree to buy but just before you are really charged, you cancel. The appstore will ask for your affinity account details... a few minutes after that you will be able to register you apps. Just start with the application where you bought the universal license, then the others. It's a shitty system and it's not even a system, more of a glitch. But now it works. Message for Affinity: fix this or at least change the information you provide.
