Googling for the error message reveals this link, which states:

If you have a newer Perl (5.8 definitely, maybe 5.6 too) and are using a UTF-8 locale, you will get many warnings from perl about "Malformed UTF-8 character" warnings. This is because the HTML output currently uses latin1, which doesn't validate as UTF-8 (unless I am mistaken, this would occur for any input that didn't validate against the locale's encoding even without a UTF-8 locale).

This problem can be worked around by telling perl to treat the input data as byte data rather than character data by adding the "use bytes;" pragma.

"When you are faced with a dilemma, might as well make dilemmanade. "