PHP Fatal error: require() [<a href='function.require'>function.require</a>]: Failed opening required 'includes/templates/template_default/templates/tpl_FILENAME_SUBSCRIBE_default.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/******/public_html/******.com/********/includes/templates/template_default/common/tpl_main_page.php on line 122

Can anyone tell me why I am getting fatal errors in my logs. Seems to be taking my site down at the same time. These are not files I have ever messed with.