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

 PLI conversion error at or near opcode_name

    Facility: DEBUG, VMS Debugger

    Explanation: An error occurred in the PL/I RTL performing a data
    type conversion, for the object <opcode_name, !AC>.

    User Action: Reenter the command, specifying a legitimate object
    for the operation desired.