Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, first array member is not a valid class name or object in /customers/4/b/6/shadowart.se/httpd.www/wp-content/plugins/jetpack/class.jetpack-sync.php:47 Stack trace: #0 /customers/4/b/6/shadowart.se/httpd.www/wp-content/plugins/jetpack/modules/enhanced-distribution.php(12): Jetpack_Sync::sync_posts('/customers/4/b/...') #1 /customers/4/b/6/shadowart.se/httpd.www/wp-content/plugins/jetpack/class.jetpack.php(1142): require('/customers/4/b/...') #2 /customers/4/b/6/shadowart.se/httpd.www/wp-includes/plugin.php(496): Jetpack::load_modules('') #3 /customers/4/b/6/shadowart.se/httpd.www/wp-settings.php(237): do_action('plugins_loaded') #4 /customers/4/b/6/shadowart.se/httpd.www/wp-config.php(90): require_once('/customers/4/b/...') #5 /customers/4/b/6/shadowart.se/httpd.www/wp-load.php(37): require_once('/customers/4/b/...') #6 /customers/4/b/6/shadowart.se/httpd.www/wp-blog-header.php(12): require_once('/customers/4/b/...') #7 /customers/4/b/6/shadowart.se/httpd.www/index.php(17): require('/customers/4/b/...') #8 {main} thrown in /customers/4/b/6/shadowart.se/httpd.www/wp-content/plugins/jetpack/class.jetpack-sync.php on line 47