3.2.5.8 Handling Out-of-Sequence or Unrecognized Messages
If the server receives a message that is not expected according to the Licensing PDU Flow (section 1.3.3), or a malformed or an unrecognized message, the server MUST send a Licensing Error Message (section 2.2.2.8) with an error code of ERR_INVALID_CLIENT and a state transition code of ST_TOTAL_ABORT.