command is only valid when multiprocess support is enabled

    Facility: DEBUG, VMS Debugger

    Explanation: The debugger was unable to execute the specified
    command since it is only valid when the debugger's multiprocess
    support is enabled.

    User Action: Restart the debugging session with multiprocess
    support enabled. Multiprocess support is enabled by defining the
    logical name DBG$PROCESS as follows: ($ DEFINE/JOB DBG$PROCESS
    MULTIPROCESS)