Fatal error: Uncaught Error: Class "App\Extension\AbstractPlugin" not found in C:\xampp\htdocs\gnu_7\g7\plugins\_bundled\gnuboard7-hello_plugin\plugin.php:15 Stack trace: #0 {main} thrown in C:\xampp\htdocs\gnu_7\g7\plugins\_bundled\gnuboard7-hello_plugin\plugin.php on line 15