Since I downloaded the latest ios9 update, screen rotate no longer works, why? And how do I enable again?
Have you checked your setting to make sure you didn't accidentally turn orientation lock on? You could have accidentally hit the portrait lock icon on the lock screen if you pull up the bottom portion of the screen that allows you to open some features without unlocking (airplane mode, flashlight, etc). Portrait lock would be the last icon on the top row...a lock with a semi circle going around it. Hope that makes sense.
https://support.apple.com/en-us/HT204547
Might explain it better.