Whoops \ Exception \ ErrorException (E_ERROR) HELP Call to a member function init() on null

[ispcpr]

C:\xampp\htdocs\kit\vendor\skyronic\crudkit\src\CrudKit\Controllers\MainController.php
            return "";
        }
    }
    public function handle_view_page () {
        // Handle the view page action
        $pageId = $this->url->get('page');
        $this->page = $this->app->getPageById($pageId);
        $this->page->init($this->app);
        ValueBag::set("pageId", $this->page->getId());

when i load index.php, aplication not open and get that error.