Nothing Is connected to my iPad Pro and I keep getting the message this accessory is not supported

Welcome to the Apple Support Communities!

I understand you are seeing a message "this accessory is not supported by this device" on your iPad Pro but you have nothing connected to it. Did you recently have it connected to a cable or charger? Do you have a smart cover or keyboard attached to your iPad Pro? Try turning your iPad off and then back on again. If the issue persists after restarting, you may need to have your iPad Pro inspected by an Apple Store Genius or an Apple Authorized Service Provider.
Find Locations - Service - Apple Stores and Apple Authorized Service Providers
Take care.

Hi rufus49. There have been a few problems reported with the Apple Smart Keyboard. Try taking your device to an Apple store, as already suggested. Make an appointment.