Why cant i build the scene?

So im having a problem here and i dont know how to solve it. I build my scene and everything seems to work just fine untill i try to simulate it, when i simulate it, it sais that there is 2000 objects that needs to be build. As you can imagine thise gives me so much lagg in the simulation that im not even able to move. Anyone got a clue why this isent working?

Hi Christoffer,

I have recently added a Swarm Agent Troubleshooting guide that will cover a lot of the common issues when building lighting.

For your specific issue have a look at this and try the steps indicated: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

Thank you!