invalid argument list for 'the debugger_command_segment'

    Facility: DEBUG, VMS Debugger

    Explanation: There is an error with the argument list. The
    Debugger may be expecting an argument list when none was
    supplied. The Debugger may have found an argument list where
    one was not expected. The Debugger may have found an argument
    list that was too long or too short. Finally, the Debugger may
    have found an inconsistency in the argument list.

    User Action: Correct the command. Supply the correct argument
    list if one was missing or in error. Delete the inappropriate
    argument list, if one was present.