Hello,
Please check your file permissions of all your php scripts, php files should be set to 644 and any file that requires writing permissions should be set to 755 (usually config files e.g config.php). Also if you use rewrite_mod for any software you're using please ensure Rewritebase / is inside your .htaccess file. Also if any php scripts execute for more than 60 seconds they will be killed by the server and produce this error. If you have any further problems please re-open this ticket by going to the "administrative" button at the top of the original post.