I am new to Fork (installed fork and i made a theme using the theming guide) and i am trying the module guide now
(https://docs.fork-cms.com/documentation/detail/module-guide)

Installing this module gave a 500 error,
The installation proces isn't completed and if i go to edit group permissions i got following message (debug mode on)

Compile Error: Declaration of Backend\Modules\MiniBlog\Actions\Add::execute() must be compatible with Backend\Core\Engine\Base\Action::execute(): void

Where can i find how the new core works ? Because the documentation describes spoon and not Symfonie
Thanks in advance for pointing me in the right direction.