iMessage activation error

Problem with imessages for about 3 weeks. Not being able to login to it. Called Apple -resolved issue by resetting PRAM Restart while holding Command-Option-P-R at same time. Wait until you hear at least 3 chimes (about 30 sec. between each) and then release the keys. Simply put, hold for about 3 minutes. Problem solved no more "error during activation" Hope this helps someone else out there.........