Why don't many libraries work in laravel 5.1?

Question

Composer

I connect libraries through the composer. I add settings to config\app.php. And they don't work. And everyone has the same error.
ReflectionException in Container.php line 737:
Class image does not exist
-------------------------------
Class cart does not exist
- ------------------------------
And so on....
How to fix them for 5.1? In 5.0 they work.

Answer 1

composer update and add classes

Answer 2

For example https://github.com/Crinsane/LaravelShoppingcart . In the App, everything is as in the instructions

Stanislav Pochepko I understand that everything is as in the instructions. But I mean maybe you have a fingerprint or something else?!
And so I used this package ~ half a year ago, everything was fine.
When writing this message, the thought came to me, maybe you immediately write "provider" and "alias" in "config/app.php". That is before "composer install/update"?! It is necessary to install the package itself from the beginning and then you need to register "provider" and "alias".