MPLIR05309E ONCODE 99140: The UNDEFINEDFILE condition was raised because a DD statement was not used in (FILE=dd-name).

At OPEN time it has not been possible to associate the logical FILE with a physical file.
Resolution:
Check that, unless the file is SYSIN or SYSPRINT, the program has been compiled with the -defext option, and that, if using JCL, there is a DD statement and, unless it is an OUTPUT file, the physical file already exists.
Module:
MF1IO.PL1