Recode:

Apple says it has identified and fixed a bug that caused some people to have their phones and tablets rendered unusable after updating to iOS 10.

“We experienced a brief issue with the software update process, affecting a small number of users during the first hour of availability,” an Apple representative told Recode. “The problem was quickly resolved and we apologize to those customers. Anyone who was affected should connect to iTunes to complete the update or contact AppleCare for help.”

It wouldn’t be Update Day without some issues that affect a small percentage of users. It brings home the point I’m constantly having to make – don’t update your device OS unless you have a recent backup of it.