# PC Freeze When Building Lightning **URL:** \ **Category:** Rendering\ **Tags:** freeze, building-lighting, unreal-engine, crash, bug-report, question\ **Created:** [March 24, 2019, 3:58pm UTC](https://forums.unrealengine.com/t/pc-freeze-when-building-lightning/445895 "2019-03-24T15:58:33Z")\ **Posts on this page:** 1\ **Showing post:** 8
**Author:** ![Aphermion](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/aphermion/32/538920_2.png) [@Aphermion](https://forums.unrealengine.com/u/Aphermion)\ **Post date:** [March 25, 2019, 2:52pm UTC](https://forums.unrealengine.com/t/pc-freeze-when-building-lightning/445895/8 "2019-03-25T14:52:16Z")
I found this: “Lightmass will Crash if it runs out of memory. This is often reported as a bug, but it is simply a limitation of your system setup” Source: > **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)** > > After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — ue4community.wiki! You will be able to find content from the official... Although I’m not entirely convinced that this is what is happening to you. Maybe you can try to further optimize the scene, so turning down light map resolution of your objects and placing lightmass importance volumes --- _[View the full topic](https://forums.unrealengine.com/t/pc-freeze-when-building-lightning/445895)._