Fatal error: Uncaught Error: Call to undefined function add_filter() in /nfs/bronfs/uwfs/hw00/d88/ecc/wordpress/wp-content/plugins/jetpack/jetpack_vendor/automattic/jetpack-classic-theme-helper/src/content-options/featured-images.php:88 Stack trace: #0 {main} thrown in /nfs/bronfs/uwfs/hw00/d88/ecc/wordpress/wp-content/plugins/jetpack/jetpack_vendor/automattic/jetpack-classic-theme-helper/src/content-options/featured-images.php on line 88