I have a 4.19 project that is only two levels, but they both build & compile without issue. When I open 4.20 or 4.21 and import the project to upgrade it, everything works fine but I can’t build lighting in one level because of the “Compile Unreal Lightmass” error. I assumed it was related to the Swarm Agent. Most of Google and the forums say I need to open a .sln file in Visual Studio but I’ve been using the Epic Games Store application to download and run the engine. What steps do I need to take to fix this? Thank you 