laravel 5.1 middleware cannot be called in controller

Question

1. Create middleware

2. $routeMiddleware is added in the Kernel class

According to the examples in the document, the first method is to add middleware in the route and it can be executed. The second method is to report an error that the class does not exist in the controller. I am new to laravel, please give me some advice.

ReflectionException in Container.php line 736:
Class Old does not exist

Answer 1

Solved the case problem and made it case-sensitive