دوستان بنده سیستم یکی از سایت هام wordprese در پنل ادمین در قسمت نمایش-> سفارشی سازی میرم این ارور میاد
Fatal error: Uncaught exception 'Exception' with message 'Expected single stylesheet key.' in /home/sabad/public_html/wp-includes/customize/class-wp-customize-custom-css-setting.php:76 Stack trace: #0 /home/sabad/public_html/wp-includes/class-wp-customize-manager.php(4129): WP_Customize_Custom_CSS_Setting->__construct(Object(WP_Customize_Manager), 'custom_css[voic...', Array) #1 [internal function]: WP_Customize_Manager->register_controls(Object(WP_Customize_Manager)) #2 /home/sabad/public_html/wp-includes/class-wp-hook.php(298): call_user_func_array(Array, Array) #3 /home/sabad/public_html/wp-includes/class-wp-hook.php(323): WP_Hook->apply_filters('', Array) #4 /home/sabad/public_html/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #5 /home/sabad/public_html/wp-includes/class-wp-customize-manager.php(734): do_action('customize_regis...', Object(WP_Customize_Manager)) #6 [internal function]: WP_Customize_Manager->wp_loaded('') #7 /home/sabad/public_html/wp-includes/class-wp-hook.php(298): call_user_func_array(Array in /home/sabad/public_html/wp-includes/customize/class-wp-customize-custom-css-setting.php on line 76

چگونه مشکل را رفع کنم؟