Fatal error: Uncaught Error: Call to undefined function add_filter() in /home/almouadj/public_html/shahbaTheme/includes/theme_update/theme-update-checker.php:56 Stack trace: #0 /home/almouadj/public_html/shahbaTheme/includes/theme_update/theme-update-checker.php(43): ThemeUpdateChecker->installHooks() #1 /home/almouadj/public_html/shahbaTheme/includes/theme_update/config.php(7): ThemeUpdateChecker->__construct('shahbaTheme', 'http://shahbaso...') #2 {main} thrown in /home/almouadj/public_html/shahbaTheme/includes/theme_update/theme-update-checker.php on line 56