Site Daemon
The 500 Internal Server Error is a very general HTTP status code that means something has gone wrong on the web server but the server could not be more specific on what the exact problem is.
Try this -- Upload a fresh copy of .htaccess file and after that go to your CPANEL error log to investigate further what had happen.
If you're web site is on a shared hosting it could be that it is disabled due using to much resources.