Fatal error: Uncaught Error: Class 'WP_Customize_Setting' not found in /home/muvaimar/public_html/wp-includes/customize/class-wp-customize-background-image-setting.php:17 Stack trace: #0 {main} thrown in /home/muvaimar/public_html/wp-includes/customize/class-wp-customize-background-image-setting.php on line 17