The logical unit sent a command to VTAM® improperly. If SSCPFM=USS3270 is specified for a logical unit, the logical unit can enter input using the ENTER key, the CLEAR key, the System Request key, or a magnetic card reader. If SSCPFM=USSSCS is specified for a logical unit, the logical unit must not issue a Clear, Cancel, or Signal request, and it cannot send a zero-length command. All logical units must send the character-coded command as a single-request chain.
The command is not executed.
Reenter the command. Some of the invalid commands mentioned above are sent when program function (PF) keys are pressed. Terminal users should avoid pressing these keys.