Fatal error: Uncaught Error: Interface "Illuminate\Contracts\Support\Htmlable" not found in C:\WebServer\htdocs\bookshelf\app\Activity\Notifications\MessageParts\ListMessageLine.php:12 Stack trace: #0 {main} thrown in C:\WebServer\htdocs\bookshelf\app\Activity\Notifications\MessageParts\ListMessageLine.php on line 12