There are two steps we should do.
First, Reset the iPad by holding down on the sleep and home buttons at the same time until the Apple logo appears on the screen.
Once the reset is complete, try to pair or connect your keyboard to the ipad again.
If it still wont work.. I strongly suggest you make a backup of your ipad using either itunes, or icloud
.. ( because the next steps will erase your settings / data )
Once the backup is made.. Lets try a reset of the ipad
On the ipad go to Settings>General>Reset>Reset all settings
Once that is complete, turn the ipad off, then on.. And then try to set up your keyboard again.
If it still isnt working.. We shoud consider a full factory reset of the ipad.. This may seem like an extreme step.. But as with most apple IOS updates. A factory reset of the device is often the only way to cure a swarm of errors that the IOS updates bring with them.
Lets try the first two steps above.. And if they dont work or you get stuck, send me a reply. And we can discuss the factory reset if needed.
I strive to provide great service, and greatly appreciate a rating of excellent below when you are satisfied.. I always answer follow up questions.
Senior Technician and Network Switching Systems Operator / Maintainer.