DESCRIPTION: NAT: Receiving "Error: Unknown Service Class"
Receiving the following “Error: Unknown Service Class” when creating NAT policy.
Resolution or Workaround:
This error indicates that the Original Service and Translated Service are not of the same type (TCP/UDP).In the instance above, the Original Service is just TCP 3391, but the Translated Service contains TCP and UDP 3389.
To correct/avoid this error, be sure to pick a Translated Service with the correct protocol.As seen in this example: