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/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-content/plugins/jetpack/class.jetpack-sync.php:66 Stack trace: #0 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-content/plugins/jetpack/modules/post-by-email.php(21): Jetpack_Sync::sync_options('/customers/8/b/...', 'large_size_w', 'large_size_h', 'thumbnail_size_...', 'thumbnail_size_...', 'medium_size_w', 'medium_size_h') #1 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-content/plugins/jetpack/class.jetpack.php(924): require('/customers/8/b/...') #2 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-includes/class-wp-hook.php(292): Jetpack::load_modules('') #3 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters(NULL, Array) #4 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-includes/plugin.php(484): WP_Hook->do_action(Array) #5 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-settings.php(423): do_action('plugins_loaded') #6 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-config.php(102): require_once('/customers/8/b/...') #7 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-load.php(37): require_once('/customers/8/b/...') #8 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-blog-header.php(13): require_once('/customers/8/b/...') #9 /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/index.php(17): require('/customers/8/b/...') #10 {main} thrown in /customers/8/b/d/hyllenstam.se/httpd.www/wordpress/wp-content/plugins/jetpack/class.jetpack-sync.php on line 66