[SOLVED] Error: Controller could not be found

Upgraded to latest 3.6 and no matter what I try to load I get:

Error: Controller could not be found.

In other words no routes or controllers work now, but in 3.5 everything worked, what gives?

try to clear tmp/cache folder and check if ur Application.php are up to date

Thanks for reply, I had cleared cache and temp views. I changed

    add(new RoutingMiddleware($this, '_cake_routes_'));
    ->add(new RoutingMiddleware($this));

And all seems to work now.