Light emitter with warmup crashes the engine

Development Rendering
1

Combining high-quality lights and warmup time in a particle emitter leads to a very unstable actor that crashes the engine in certain situations. Here is one I’ve managed to consistently recreate:

  1. Create a new particle system.
  2. Add a Light to the emitter, and check “High Quality Lights”.
  3. Set the system’s Warmup Time to 5.0, and save it.
  4. Create a new map. Maximize the Perspective view, and disable Realtime.
  5. Place the particle system in the map and save it.
  6. Reload the map. You might need to do this twice if Realtime was on before the map was created.

The editor will now say “Fatal error!” and crash with no other information. I’ve recreated the issue in both 4.11 and 4.13. I’ve also seen it crash after exiting PIE, but not every time.

2

Hey ,

Thanks for the clear and precise repro steps. I was able to confirm what you are reporting and have gone ahead and entered a bug report for the issue. You can track the issue following the link below on our new Public Issues Tracker.

UE-37020

Once the issue has been addressed by our engineers, the fix will be added to the release notes for fixed issues within an upcoming full engine or hotfix release.

Let me know if you have further questions or need additional assistance.

Cheers,