iBooks

These are user-to-user forums, you are not talking to iTunes Support nor Apple.

You've tried the 'standard' troubleshooting e.g.

- closing the app (and other apps) via the iPad's taskbar : iOS: Force an app to close.

- soft-reset : 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.

You could also check the iBooks settings : Settings > iBooks - try turning off 'online content' and the 'sync' settings and see if that makes any difference.

This worked for me and several others, from a post from MrsMike921 in the following thread:

https://discussions.apple.com/thread/6568835

go to your settings, and first go to Safari and delete your history by scrolling down to "clear history and website data". Then go to the advanced settings and select ""website data". It should show 0 bytes. If not, clear again.

next go to iTunes and App Store in settings, and touch your Apple ID, the select sign out.

AFter you you sign out of your ID, restart your iPad by holding down the power button and home key simultaneously until you see the apple logo after the restart.

when you are powered up, go to iBooks. You should get a message that you need to sign in to sync up your books. Sign in, and that should do it.