this computer is no longer authorized for applications that are installed

[SGSErwin]

I suddenly got the message saying 'This computer is no longer authorized..." so I clicked to authorize, then got a message saying 'This computer is already authorized.." and telling me it is one of 3 authorized. So I clicked OK, and then it came back with the same 'not authorized' message. It now does that repeatedly, no matter how many times I restart the devices. This only occurred after I updated iTunes yesterday to the latest version. It tells me that if I don't authorize it can't sync, can't back up, and will delete my apps. So I'm completely stuck. Please help!!

 

[willerz2]

Sign out of your AppleID, and close out iTunes altogether. Stop the iTunes process if it's still there. Restart iTunes, and re-authorize the PC again. If that does not fix the issue, you may have to delete the local library.plist and try again, or delete it, and remove iTunes, then install a lower version of iTunes.