If you have an older iPad, you might want to steer clear of the latest iOS 9.3 update.
According to numerous reports, it appears that after installing the new update, some users are receiving an authentication error message when they try to activate their iPad, leaving the tablet bricked and unusable.
Apple hasn't offered up its own fix yet or officially commented on the issue, though the company's support arms are at least aware of the problem.
For now, if you have an older iPad, it may be best to wait until Apple fixes the issue before you update to iOS 9.3. If you do attempt the update, at least back up your iPad to iCloud or your computer before you try, just in case something does go wrong.