直到昨天早上（12小时前）一切都很好。但现在每个PHP页面都显示"500内部服务器错误"。请查看此链接http://abusadat.com.这是一个WordPress网站。我认为这是关于WordPress的。
但我有一个子域，其中有一个PHP文件-http://demo.abusadat.com/fb-apps/index.php，得到相同的错误。虽然在同一位置，但有一个HTML文件http://demo.abusadat.com/fb-apps/test.html，运行良好。为了测试PHP页面中是否有任何语法导致该错误，我在"index.php"文件的第一行放置了一个"die('some message')"，但它显示了相同的错误。该子域中没有HTAccess。
一切都在工作——突然所有的PHP都停止了，我无法解决这个问题。有人能帮忙吗？
编辑：*cPanel的最新错误日志*
[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
谢谢，萨达特
您应该检查日志文件，以确定在问题首次出现时是否发生了自动更新。还要检查Apache（或您的web服务器）是否在那个时候重新启动，激活了以前的更新。