Description:
A GPU crash issue has been identified in Unreal Engine 5.5 affecting projects using Lumen and primarily on Intel hardware. The problem stems from a group barrier inside a divergent branch in ScreenProbeConvertToIrradianceCS.
Potential Impact:
Critical: A GPU crash may occur or other instability, most likely on Intel hardware.
Solution:
A fix is now available that ensures GroupMemoryBarrierWithGroupSync is no longer called from inside a divergent branch. This fix has been integrated into the 5.6 release of Unreal Engine in CL#42412951 (dc36f63).
Integration Notes:
- Integrate CL#42243010 (215041) via your preferred code integrating utility (p4, git cherry-pick, etc)
- After integration, rebuild your full project to apply changes.
See 🛠️ Tech Note: Fix for GPU Crash in Lumen in Unreal Engine 5.5 | Knowledge base for additional details