Only the Github version should -need- to compile lightmass. Something with your launcher build is bugged, and yes, it -is- only you, I’ve never seen this before. Try just deleting the engine, manually deleting any files left over in the engine folder, and redownloading it, should fix it.
So in the future whenever “Light build failed. Swarm failed to start. Rebuild Unreal Lightmass” happens again(it has already happened many times), then deleting Epic Launcher and reinstalling it will solve the problem correct? Don’t need to get the github to compile lightmass?
Unless you’re using the Git version of Unreal, which you DO need to compile lightmass, it shouldn’t be happening in the first place. Something’s messed up with your downloads, maybe a firewall or something. Hard to say from here without actually looking at it.
Without compiling lightmass, you can’t build ANY lighting in your project. Which is exactly the same problem I’m having now. I migrated my level into a new C++ project just so I can be able to rebuild unreallightmass.cpp in VS but the stupid "programs folder’ is also missing. Its been a year since the last post and this freaking problem still exists.
I’m having this issue and I’m getting it routinely, so is a team member. We aren’t using a custom launcher, just the normal one. It’s coming up randomly in different projects.
It’s so frustrating. When I google it people tell me to recompile this stuff but I can’t as i’m not using a custom engine. We’ve redownloaded the engine, this problem happened in 4.19, 4.20, 4.21, with new projects…
Thanks a-million! This is what got me sorted out. I believe I had done a full compile of the UE4 solution, but maybe it didn’t include the projects folder. The first time I have ever tried to build lighting with a source version of the editor. This is a reliable failure of lightmass with UESource. I had the same issue back when I had 4.22S, but didn’t dig deep into the fix until now.
For those having other issues with lightmass, there is good documentation here. It even goes over cleaning and re-validating cache, as well and having to compile the UnrealLightmass solution from within Visual Studio, for UES.