Ever have iTunes keep asking you to authorize your Mac to play a song that was purchased from the iTunes Store? You provide the requested information and everything seems fine, but then the next time you try to play the song, iTunes asks you to authorize it again.
Courtesy of Apple
This authorization loop can continue indefinitely, and can be caused by a number of issues. Fortunately, the solution is relatively simple, and takes only a few minutes.
In the Problem Authorizing iTunes to Play Purchased Music guide, we'll take you through the fixes that will give iTunes a little whack and get it unstuck.