Building lighting is suddenly always crashing

I have a puzzle game made up of just one level filled with puzzles and now every time I tried to build Unreal and Swarm crash (plus one time I left Firefox open while the build was running and that also had all tabs crash at the same time). It usually crashes at 14% on importing static maps but sometimes will crash before or after this. I’ve never had problems building on this computer with this game up until now or building any tutorials or other small games I have made.

So far I tried:
Changing the quality of lighting.
Clearing and validating Swarm
Rolling back map changes and trying to build
Trying to build the backup file from the day before (same problem)
Changing lights in the scene from static to dynamic

Project is blueprint only and no crash log seems to be generated anywhere.

System specs: i7 8750H / GTX 1060 / 16GB RAM and Unreal and this project are on an SSD.