General 500 error from the root

I would disable .htaccess and changing the permalink structure that can be found in (setting->permalinks).

You’re specifically getting a 500 error and not a “Cannot connect to the Database” error?

Since it sounds like a theme issue, inside of wp-config.php, set:
define( ‘WP_DEBUG’, true );
define( ‘WP_DEBUG_LOG’, true );
define( ‘WP_DEBUG_DISPLAY’, true);

so you can start seeing exactly what errors are occurring

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)