Slim Application Error

The application could not run because of the following error:

Details

Type: Error
Message: Call to a member function toArray() on null
File: /home/wsvce71/domains/wsvceresfifo.nl/public_html/App/Controller/Cms/AlbumController.php
Line: 34

Trace

#0 [internal function]: App\Controller\Cms\AlbumController->detail(Object(Slim\Http\Request), Object(Slim\Http\Response), Array)
#1 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/Handlers/Strategies/RequestResponse.php(41): call_user_func(Array, Object(Slim\Http\Request), Object(Slim\Http\Response), Array)
#2 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/Route.php(335): Slim\Handlers\Strategies\RequestResponse->__invoke(Array, Object(Slim\Http\Request), Object(Slim\Http\Response), Array)
#3 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(117): Slim\Route->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response))
#4 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/Route.php(313): Slim\Route->callMiddlewareStack(Object(Slim\Http\Request), Object(Slim\Http\Response))
#5 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/App.php(495): Slim\Route->run(Object(Slim\Http\Request), Object(Slim\Http\Response))
#6 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(117): Slim\App->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response))
#7 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/App.php(388): Slim\App->callMiddlewareStack(Object(Slim\Http\Request), Object(Slim\Http\Response))
#8 /home/wsvce71/domains/wsvceresfifo.nl/public_html/vendor/slim/slim/Slim/App.php(296): Slim\App->process(Object(Slim\Http\Request), Object(Slim\Http\Response))
#9 /home/wsvce71/domains/wsvceresfifo.nl/public_html/App/Application.php(49): Slim\App->run()
#10 /home/wsvce71/domains/wsvceresfifo.nl/public_html/index.php(31): App\Application->run()
#11 {main}

Notice: Trying to get property 'private' of non-object in /home/wsvce71/domains/wsvceresfifo.nl/public_html/App/Controller/Cms/AlbumController.php on line 28