Thank you for using Apple Support Communities. It's my understanding you're receiving an error message when trying to activate Touch ID on your iPad. I've got some steps that can resolve this issue. Please follow the remaining steps below. Try using Touch ID after each step:
Get help with Touch ID on your iPhone or iPad
- Make sure that you have the latest version of iOS.
- Make sure that your fingers and the Home button are clean and dry.* For the Home button, use a clean, lint-free cloth to wipe off any dirt or debris.
- Your finger should cover the Home button completely, touching the surrounding metal ring. While Touch ID is scanning, you shouldn't tap too quickly or move your finger around.
- If you're using a case or screen protector, make sure it doesn't cover the Home button or the surrounding ring.
- Go to Settings > Touch ID & Passcode and make sure that iPhone Unlock or iTunes & App Store is on, and that you've enrolled one or more fingerprints.
- Try enrolling a different finger.
- If you can't enroll any of your fingers, take your device to an Apple Retail Store or Apple Authorized Service Provider, or contact Apple Support.