UE 5.5.4 → 5.6 Crash on Map Load with Ray Tracing Enabled — Untrackable Static Mesh Geometry Issue

Development Programming & Scripting
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I’m experiencing a persistent and untraceable crash in my project after upgrading from UE 5.5.4 to 5.6 that appears only when Ray Tracing is enabled. After weeks of debugging, I’m reaching out in the hope that someone can provide insights or potential fixes.

:wrench: Issue Description:

  • The project crashes only in a specific map, but opens and runs perfectly in other levels that use similar or even heavier Ray Tracing features.

  • The crash occurs consistently when Ray Tracing is enabled, either during map load or shortly after navigating to a certain area of the level.

  • The crash log consistently points to this assertion:
    Assertion failed: InBuildRequest.Owner->GetRHI() != nullptr
    [File: …RayTracingGeometryManager.cpp] [Line: 1368]
    Build request for FRayTracingGeometry without valid RHI. Was the FRayTracingGeometry evicted or released without calling RemoveBuildRequest()?

  • After purging actors, I can explore the map for a short time, but when I select a specific Static Mesh or enter a certain area, the crash occurs again.

  • I’ve attempted to override RT behavior using:

  • r.RayTracing.ForceAllRayTracingEffects 0

  • via Level Blueprint, which mitigates some effects — but the crash still occurs at geometry build time in some cases.

  • The Output Log shows:

RAY TRACING GEOMETRY - REQUESTED MEMORY OVER BUDGET 791.132 MiB / 400 MiB

  • Even after reducing content, this warning appears, suggesting Unreal is trying to process geometry that’s not easily visible or already removed.

:package: Current Setup:

  • Unreal Engine Version: Migrated from 5.5.4 to 5.6
  • Project Type: Single-player ARPG using Ray Tracing features
  • Hardware: RTX-enabled GPU with DX12 RTX 4090
  • Crash Reproduction: 100% reproducible when Ray Tracing is on and the problematic map is loaded or navigated

:red_question_mark:What I’m looking for:

  • Is there a way to fully disable Ray Tracing geometry compilation per map, before the level loads?
  • How can I flush or reset RHI geometry references for a map that was corrupted during previous RT builds?
  • Is there a way to force the engine to ignore certain Static Meshes or geometry at Ray Tracing compile-time?
  • Can this type of crash be triggered by ghosted, out-of-bounds, or **residual geometry references?

If anyone from Epic or the community has faced a similar GetRHI() error or Ray Tracing memory budget crash, I’d be extremely grateful for your insights. I’m committed to solving this and will gladly share results for others once resolved.

Thanks in advance for your time and support!