Thank you! This was the solution for me as well. I was playing around, getting my feet wet with C++ but I made the mistake of trying to create a C++ class in the editor without first having the C++ toolchain for Visual Studio installed first. I got errors in my Output Log telling me that I needed the C++ toolchain installed first. So I did that but then…
This caused all sorts of weird anomalies while trying to debug and edit code, etc. So I desperately wanted to start over with the C++ thing now that I had the toolchain properly pre-installed. I didn’t need to keep any of the classes I created, so I deleted all the source files in the Source and Binaries folder, but then I got the “following modules are missing” popup when trying to launch the editor, which brought me here.
Removing the entire “Modules”: [ {…} ] section for the .uproject file did the trick for me. Removing it, along with the Source, Intermediate and Binary folders, successfully got my project back to a working, pre-C++ state.