ICLOUD IS GREYED OUT AFTER UPDATING TO IOS 8

If you mean it's greyed out in Settings, go to Settings>General>Restrictions>Accounts (near the bottom) and set this to Allow Changes.

Is it greyed out in Settings so when you try to go to Settings, then tap iCloud, it won't open? If not, describe exactly what you are experiencing.

Also, if you haven't already tried, rest your iPad by holding the sleep/wake and home buttons at the same time until you see the Apple logo, then release and wait for it to restart. See if that helps.

Did you back it up before updating it?

You may need to restore it, then restore your backup. Restore it as explained here: Use iTunes to restore your iOS device to factory settings. Then restore your iTunes backup.

Skip the second step...don't create a new backup or it will overwrite your existing backup. You don't want to back up your phone it its current state. Just restore it, then restore the backup you made before updating it.

I would go ahead and back it up, then restore it anyway to see if that might fix it.

Same thing happened to me - solution is to go to Settings -> Mail, Contacts & Calendars -> Add Account

Then choose iCloud, enter your details and this adds your iCloud account to you iPad.

IM SO HAPPY IT WORKED FOR ME ANYWAY ...THANKS!!

This also fixed my problem in December 2015 on a 6S running iOs 9.2

thanks allot. Finally someone helps!