警告：参数1到wp_default_styles（）应该是一个引用，给定的值

I ran this code through a debugger; it returned with no faults.

do {
    foreach ( (array) current($wp_filter[$tag]) as $the_ )
        if ( !is_null($the_['function']) )
            call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));

} while ( next($wp_filter[$tag]) !== false );

array_pop($wp_current_filter);

Warning: Parameter 1 to wp_default_styles() expected to be a reference, value given in /homepages/27/d653904259/htdocs/clickandbuilds/Jellyx/wp-includes/plugin.php on line 600

Line 600:

    call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));

Update WordPress or try adding

define('WP_DEBUG', false);

to wp-config.php.