Why can’t I use my apple id

If not an App Store/iTunes problem, is the ID disabled?

If your Apple ID is locked or disabled - Apple Support.  

Hello Lknigt, 

Thank you for using Apple Support Communities!

We understand from your post that you cannot use your Apple ID. If your account has been disabled in the App Store and iTunes, this article has steps which may help: 

If you see a message that says 'Your account has been disabled in the App Store and iTunes' - Apple Support

Best Regards.