Locked Out, Forgot Lock or Restrictions Passcode, or Need to Restore Your Device: Several Alternative Solutions
Forgotten Restrictions Passcode Help
You will need to restore your device as New to remove a Restrictions passcode. Go through the normal process to restore your device, but when you see the options to restore as New or from a backup, be sure to choose New.
Also, see iTunes- Restoring iOS software.
Same thing happened to me. I updated the iOS software and the next time I used it, the iPad needed a passcode that I did not set-up! Now I made it worse by guessing at the passcode and now I it is disabled.
iPad is disabled
connect to iTunes
You can probably tell I am not in love with Apple . If I have to reset an lose everything, I will sell the ipad and buy a Surface Pro.