01-18-2018 12:56 AM
Check this list of ClearPass error codes to find that 216 is User authentication failed.
If you search on the code 0xc000006d, you can see that the AD basically rejected the authentication and it can be for a number of reasons, like bad username, bad password, expired account, but also a clock mismatch between ClearPass and the AD.
I would double check the clock/time on ClearPass and AD, the account, and if that appears all correct, you can try to leave and join the domain to see if that helps.
Otherwise please work with Aruba TAC to do real-time troubleshooting.
If you have urgent issues, please contact your Aruba partner or Aruba TAC (click for contact details).