Can't open Debug Mode of project because of: The following modules are missing or build with a different engine

Hello. I am working in a Blueprint project and just started with C++. I created my first Script and wanted to compile it in the Debug Version of my Project but I got the Error "The following modules are missing or build in a different Engine version -ProjectName- would you rebuild it now. I can pen my Project but when I open Visual Studio and click on Debug this Error appears. I know there are many tips to fix this Error in the Internet but I didn’t found one solving exactly this problem.
They are only for fixing problems after somebody imported a new Plugin or sth like that.

Can somebody help me?