OMG...please don't chmod 777! That is a severe security risk since it allows anyone to do whatever they wish to that file. Better option is to find the user that this should run under and do a chmod to add only that user with execute permissions. The user may be "mythtv" or "user_1" or similar... Try those options first. IMHO, 777 should never be an option.
Kindest Regards,
Sevak