Unreal freezes while finishing lighting build

whenever i try to build lighting, it always gets stuck at “collecting the scene”, and it says the build process is at 100%, and it just freezes. i have tried changing swarm settings as well as setting the static level lighting scale to 4. the map this is on isn’t very large, and it happens even on the sample level for the third person project. I’ve even left the project open overnight, and nothing changed.