How to Turn Off (Hide) PHP Pop up Errors or warnings in WordPress

Описание: define('WP_DEBUG', true);
It is also possible, that this line is already set to false. In that case, you’ll see the following code:
define('WP_DEBUG', false);
In either case, you need to replace this line with the following code:
ini_set('display_errors','Off');
ini_set('error_reporting', E_ALL );
define('WP_DEBUG', false);
define('WP_DEBUG_DISPLAY', false);