You are missing a use statement. Because CakePHP 3.0 uses namespaces, you have to either use the fully namespaced classname Cake\Routing\Router or add use Cake\Routing\Router to the top of your view file.
https://github.com/cakephp/cakephp/issues/3909
You are missing a use statement. Because CakePHP 3.0 uses namespaces, you have to either use the fully namespaced classname Cake\Routing\Router or add use Cake\Routing\Router to the top of your view file.
https://github.com/cakephp/cakephp/issues/3909