I have a problem with cloning a repo from github. Right now I want to import the project from my repository into GitHub, so I start Intellij, I select Checkout from from Version Control, then I use the git url and create an existing project .. Everything is fine. Intellij gets this project from github, but when I use another branch from this repository and I will modify the java class in this project, I have more problems because something is working correctly. I can not create a new class, all java files look like this: 
The hint in Intellij does not work, and I cannot access another class in the src package. I can not start and debug this project.
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