Fatal Error Function.require?

This is the error I am getting.

Warning: require(/home/commmkta/public_html/wp-includes/category.php) [function.require]: failed to open stream: Permission denied in /home/commmkta/public_html/wp-settings.php on line 131

Fatal error: require() [function.require]: Failed opening required ‘/home/commmkta/public_html/wp-includes/category.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/commmkta/public_html/wp-settings.php on line 131

Can anyone tell me what I need to do to fix it? I’ve been online with my host and they haven’t been able to fix it like they usually can.

Thanks!