Any of my php files on the server generated 500 "Internal Server Error"

Question

Everything was working fine till last morning (12 hours ago). But now each of PHP page is showing "500 Internal Server Error". Please look at this link http://abusadat.com. It's an WordPress site. I have thought it's about WordPress.

But I have a sub-domain, where there is a single PHP file - http://demo.abusadat.com/fb-apps/index.php, which gets same error. Though at the same location, there is a HTML file http://demo.abusadat.com/fb-apps/test.html, which works fine. To test if any syntax in PHP page causes that error, I have placed a "die('some message')" at the first line of that "index.php" file, but it shows same error. There is no HTAccess in that sub-domain.

Everything was working - suddenly all PHP stopped, I can't get the problem. Can anyone help?

Edited: *Latest Error log from cPanel*

[Mon Jun 27 14:42:30 2011] [error] [client 59.93.241.43] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:42:30 2011] [error] [client 59.93.241.43] File does not exist: /home/abusadat/public_html/demo.abusadat/favicon.ico
[Mon Jun 27 14:42:29 2011] [error] [client 59.93.241.43] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:42:29 2011] [error] [client 59.93.241.43] File does not exist: /home/abusadat/public_html/demo.abusadat/favicon.ico
[Mon Jun 27 14:42:26 2011] [error] [client 59.93.241.43] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:42:26 2011] [error] [client 59.93.241.43] File does not exist: /home/abusadat/public_html/demo.abusadat/favicon.ico
[Mon Jun 27 14:40:53 2011] [error] [client 70.176.105.10] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:40:53 2011] [error] [client 70.176.105.10] File does not exist: /home/abusadat/public_html/demo.abusadat/favicon.ico
[Mon Jun 27 14:40:53 2011] [error] [client 70.176.105.10] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:40:53 2011] [error] [client 70.176.105.10] File does not exist: /home/abusadat/public_html/demo.abusadat/favicon.ico
[Mon Jun 27 14:40:53 2011] [error] [client 70.176.105.10] File does not exist: /home/abusadat/public_html/demo.abusadat/500.shtml, referer: http://stackoverflow.com/questions/6497358/any-of-my-php-files-on-the-server-generated-500-internal-server-error
[Mon Jun 27 14:40:00 2011] [error] [client 180.234.41.26] File does not exist: /home/abusadat/public_html/demo.abusadat/500.shtml
[Mon Jun 27 14:39:48 2011] [error] [client 180.234.41.26] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:39:48 2011] [error] [client 180.234.41.26] File does not exist: /home/abusadat/public_html/demo.abusadat/fb-app
[Mon Jun 27 14:39:34 2011] [error] [client 109.132.111.25] File does not exist: /home/abusadat/public_html/demo.abusadat/404.shtml
[Mon Jun 27 14:39:34 2011] [error] [client 109.132.111.25] File does not exist: /home/abusadat/public_html/demo.abusadat/favicon.ico

Thanks, Sadat

Answer 1

You should check your log files to determine if an automatic update occurred around the time the problem first appeared. Also check if Apache (or your web server) was restarted around that time, activating a previous update.