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 /home/public/wp-content/plugins/jetpack/class.jetpack-sync.php:39 Stack trace: #0 /home/public/wp-content/plugins/jetpack/modules/enhanced-distribution.php(12): Jetpack_Sync::sync_posts('/home/public/wp...') #1 /home/public/wp-content/plugins/jetpack/class.jetpack.php(924): require('/home/public/wp...') #2 /home/public/wp-includes/plugin.php(496): Jetpack::load_modules('') #3 /home/public/wp-settings.php(237): do_action('plugins_loaded') #4 /home/public/wp-config.php(90): require_once('/home/public/wp...') #5 /home/public/wp-load.php(29): require_once('/home/public/wp...') #6 /home/public/wp-blog-header.php(12): require_once('/home/public/wp...') #7 /home/public/index.php(17): require('/home/public/wp...') #8 {main} thrown in /home/public/wp-content/plugins/jetpack/class.jetpack-sync.php on line 39