That interpretation looks correct to me.
What *is* a bit puzzling is that the error message posted by the OP is being generated by UMMF.pm. The latest version of UMMF.pm on CPAN definitely has
, I guess you must have modified UMMF.pm at some stage - in which case you need to return it to its original state. If you haven't modified that file, then you either need to fix it, or install the current version of UMMF from CPAN.