Library /sys$common/syshlp/dbg$help.hlb DEBUG, Messages, ROPRANDF  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 reserved operand fault at or near opcode_name

    Facility: DEBUG, VMS Debugger

    Explanation: The debugger encountered an opcode that is reserved
    to Digital.

    User Action: If the instruction was entered by the user, reenter
    the instruction, without using an opcode reserved to Digital. If
    not, then there may be an error in the user program instructions.