marcochiesi
commented
9 years ago Hi there,
you should check your server's error_log to find more details about the error. It's possible that the cause is a too restrictive mod_security rule. You may try to disable mod_security by putting the following code snippet in the .htaccess of your site:
SecFilterEngine Off
By the way PHP 5.3 has reached end of life last year and it's no longer supported, so it's not recommended to still use it.
I am using the Genesis Framework with the Parallax Pro theme. When the plugin is activated, I get a 500 internal server error trying to access the WordPress Customizer. Can access it fine with the plugin deactivated. Works fine on development site. Development server is using PHP 5.4 while the production server is set at PHP version 5.3 (and that's as high as it goes).