"accessory Not Supported" message and the keyboard wont work.. wasnt a problem before. Cleaned the contacts - still happening. Rebooted - still happing. Any other suggestions?

"Accessory Not Supported" message showing up al of a sudden on my iPad Pro after a couple years of use. My Smart keyboard wont work. This wasn't a problem before - just since the "Accessory" message showed up. Cleaned the contacts as recommended and it is still happening. Rebooted the iPad and it is still happing. Any other suggestions? Has my Smart Keyboard gone bad?