If you're experiencing an activation error on your iPhone/other device and were previously using iOS7 beta, there's a good chance that you never upgraded to a non-beta iOS7 version and your beta has expired. So how do you fix this? Follow these steps: 1) Update iTunes to the latest version (11.1) if you haven't already 2) Plug you iPhone/iDevice into your computer. Back up the data on the device. 3) Click "Restore" on your device's page in iTunes. If this doesn't work, proceed to step 3a below. 4) Once your device is done restoring and activating you can restore your data from your iTunes backup 5) Enjoy non-beta iOS7! Step 3a) You will need to put your device into DFU mode: A) With the device still plugged in, turn it off B) Hold down the power button for 3 seconds C) Without releasing the power button, hold down the home button for 10 seconds D) Without releasing the home button, release the power button. E) Hold the home button until iTunes says it detects a device in recovery mode. F) Restore the device * If you don't get to step E and an Apple logo appears repeat step 3a. Edit 1: If you're unable to backup in iTunes due to the Find My Iphone lock just proceed without backing up. You will have to restore with your last backup (if you're using iCloud this happens once a day so you shouldn't be missing too much data). Edit 2: If you have a developer account download the latest iOS 7 version on the developer site. You can then just hit update in iTunes while holding down option and select this downloaded file. This method should retain all the current data on the phone without an need for a backup (although I'd still recommend backing up if you can).