I rented a video in iTunes and when I tried to watch it I got the following error message. MPAV controller error Doma in error 3

If you haven't already done so then try a soft-reset and see if it plays after your iPad has restarted : press and hold both the sleep and home buttons for about 10 to 15 seconds (ignore the red slider), after which the Apple logo should appear - you won't lose any content, it's the iPad equivalent of a reboot.

As you've marked your reply as having solved your problem I assume that you no longer have a problem, or was that a mistake ?

If you are still having problems playing it, and you've also tried closing the Videos app via the iPad's taskbar and tried searching for it via the iPad's spotlight search screen and seeing if that lets you play it, then try contacting iTunes Support and see if they will grant you a redownload : http://reportaproblem.apple.com/