Your hosting provider should be able to show you where 500 errors are logged.
PHP by default disables showing errors (thus a blank white screen). You can tell it to just show errors to the screen by adding something like the following to your .htaccess as well:
php_flag display_startup_errors on
php_flag display_errors on
Please note... these are server level items, not software level things. As a result, the support team cannot officially help you with this. If you have problems, you should contact your hosting provider about how they handle access to error logs and displaying errors.