The generic error.
WHAT IT MEANS
Something failed and the server could not produce a page.
It is deliberately generic.
WHAT TO CHECK, IN ORDER
The error log, which frequently names the cause .htaccess, for a syntax error File permissions, if recently changed PHP version compatibility Whether a resource limit was hit
THE .HTACCESS TEST
Rename it temporarily. If the site works, that file is the problem.
Rename it back and find the error.
THE PERMISSIONS POINT
Files set to 777 cause a 500 on some configurations.
If someone recently set permissions broadly, that may be why.
IF IT AFFECTS ONE PAGE ONLY
Application-level, not server-level. Look at that page's code or plugin.
IF IT AFFECTS EVERYTHING
Configuration or resources.
WHEN TO ASK US
If the error log shows nothing and you have checked .htaccess and permissions.
Include what you checked.
