iCloud tab in settings is greyed out
Pretty much what the title says.
I'm trying to restore my iPad 3rd gen so I can sell it and iTunes won't let me restore it as I need to turn "Find my iPad" off. The problem is that the iCloud tab in my settings menu is greyed out and I can't select it.
I've backed the iPad up to my iMac, but even after resetting the device the iCloud tab is still greyed out. Any ideas anyone before I take myself off to the Apple store.
Many thanks
iPad (3rd gen) Wi-Fi, iOS 8.1.2