Fatal error: Uncaught Error: Class 'Illuminate\Notifications\Messages\SimpleMessage' not found in /home/app/htdocs/message_gateway/vendor/laravel/framework/src/Illuminate/Notifications/Messages/MailMessage.php:5 Stack trace: #0 {main} thrown in /home/app/htdocs/message_gateway/vendor/laravel/framework/src/Illuminate/Notifications/Messages/MailMessage.php on line 5