500 Error only one one page in the WP admin

It means you have a PHP syntax error. You need to consult the logs or turn on debug mode. In wp-config.php in your root wordpress directory, find the line as follows:

define( 'WP_DEBUG', false );

and change it to:

define( 'WP_DEBUG', true );

Refresh your page that appears blank to find the error. If it still does not show up, it means you may need to change your php.ini settings to display errors.

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