original version of source file not found file used is file_
 specification

    Facility: DEBUG, VMS Debugger

    Explanation: A source file was found for some module. But the
    revision date and time or the file size indicates that this may
    not be the same version of the file that was used in the original
    compilation of the module. This warning message indicates
    that future source line displays from this source file may not
    correspond to the actual source used to compile the module.

    User Action: None, unless the original source is available.
    Then you can use the debugger command SET SOURCE to indicate
    the location of the source to the debugger.