The bundle does not work if the project is not in a bundle (symfony 3.4+)

[jibundeyare]

When I use this bundle with symfony 3.4, I get the following error when trying to create an entity.

 Entity name:
 > App\Entity\Post


 [ERROR] The bundle "App" does not exist.

In symfony 3.4+, the concept of bundle for the main app is deprecated.

Do you want some help to repair the bundle ? I found it very useful for my students, especialy when they are complete beginners.