I use the following settings to display errors in WordPress, to be added to error log.
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
define( 'SCRIPT_DEBUG', true );
error_reporting(E_ALL);
ini_set('display_errors', '0');
I add these to wp-config.php and whatch the errors log.