One of the following conditions has deemed the command message invalid:
The MP, DCC, or RCU could not understand a message it received from another component in the system.
On MP-30 system the required expansion ROM is bad or not installed correctly.
On MP-30 system the PH9 scan or probe changer options have been configured into the system, and the expansion ROMs are not on the MP CPU board.
What you should do:
To clear the error, power the MP down.
Power the MP back up.
If the error reoccurs, contact your Giddings & Lewis service representative.