Fatal error: Uncaught Error: Call to undefined function is_admin() in /var/www/andovercg/staging/wp-content/themes/astra/inc/theme-update/class-astra-theme-background-updater.php:100 Stack trace: #0 /var/www/andovercg/staging/wp-content/themes/astra/inc/theme-update/class-astra-theme-background-updater.php(393): Astra_Theme_Background_Updater->__construct() #1 {main} thrown in /var/www/andovercg/staging/wp-content/themes/astra/inc/theme-update/class-astra-theme-background-updater.php on line 100