Crash in editor when loading a procedural mesh that has multiple sections and raytracing is enabled

Download the licensee repro from here (although admittedly this might just be a standard empty project with rt enabled) - [Link Removed]

Open the project and:

• Create a new level
• In the Actors section in the Editor, search for "Demo Mesh"
• Place a "Demo Mesh" actor in the level
• Run the level
• A crash should be observed

> [Inline Frame] UE4Editor-D3D12RHI.dll!TArray<FHitGroupSystemParameters,TSizedDefaultAllocator<32>>::RangeCheck(int Index) Line 674 C+> [Inline Frame] UE4Editor-D3D12RHI.dll!TArray<FHitGroupSystemParameters,TSizedDefaultAllocator<32>>::RangeCheck(int Index) Line 674 C  [Inline Frame] UE4Editor-D3D12RHI.dll!TArray<FHitGroupSystemParameters,TSizedDefaultAllocator<32>>::operator[](int Index) Line 718 C  UE4Editor-D3D12RHI.dll!SetRayTracingHitGroup(FD3D12Device * Device, FD3D12RayTracingShaderTable * ShaderTable, FD3D12RayTracingScene * Scene, FD3D12RayTracingPipelineState * Pipeline, unsigned int InstanceIndex, unsigned int SegmentIndex, unsigned int ShaderSlot, unsigned int HitGroupIndex, unsigned int NumUniformBuffers, FRHIUniformBuffer * const * UniformBuffers, unsigned int LooseParameterDataSize, const void * LooseParameterData, unsigned int UserData, unsigned int WorkerIndex) Line 4061 C  UE4Editor-D3D12RHI.dll!FD3D12CommandContext::RHISetRayTracingHitGroups::_l2::<lambda>(unsigned int WorkerIndex) Line 4160 C  UE4Editor-D3D12RHI.dll!FD3D12CommandContext::RHISetRayTracingHitGroups(FRHIRayTracingScene * InScene, FRHIRayTracingPipelineState * InPipeline, unsigned int NumBindings, const FRayTracingLocalShaderBindings * Bindings) Line 4193 C  [Inline Frame] UE4Editor-Renderer.dll!FRHICommandList::SetRayTracingHitGroups(FRHIRayTracingScene * Scene, FRayTracingPipelineState * Pipeline, unsigned int) Line 3635 C  UE4Editor-Renderer.dll!FDeferredShadingSceneRenderer::WaitForRayTracingScene::l2::<lambda>(FRHICommandListImmediate & RHICmdList) Line 1247 C  UE4Editor-RenderCore.dll!FRDGPass::Execute(FRHIComputeCommandList & RHICmdList) Line 302 C  UE4Editor-RenderCore.dll!FRDGBuilder::ExecutePass(FRDGPass * Pass) Line 1593 C  UE4Editor-RenderCore.dll!FRDGBuilder::Execute() Line 1253 C  UE4Editor-Renderer.dll!FDeferredShadingSceneRenderer::Render(FRHICommandListImmediate & RHICmdList) Line 2618 C  UE4Editor-Renderer.dll!RenderViewFamily_RenderThread(FRHICommandListImmediate & RHICmdList, FSceneRenderer * SceneRenderer) Line 3619 C  UE4Editor-Renderer.dll!FRendererModule::BeginRenderingViewFamily::l35::<lambda>(FRHICommandListImmediate & RHICmdList) Line 3889 C  [Inline Frame] UE4Editor-Renderer.dll!EnqueueUniqueRenderCommand(FRendererModule::BeginRenderingViewFamily::l35::void <lambda>(FRHICommandListImmediate &) &&) Line 244 C  UE4Editor-Renderer.dll!FRendererModule::BeginRenderingViewFamily(FCanvas * Canvas, FSceneViewFamily * ViewFamily) Line 3881 C  UE4Editor-Engine.dll!UGameViewportClient::Draw(FViewport * InViewport, FCanvas * SceneCanvas) Line 1631 C  UE4Editor-Engine.dll!FViewport::Draw(bool bShouldPresent) Line 1559 C  UE4Editor-UnrealEd.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 1919 C  UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 426 C  UE4Editor.exe!FEngineLoop::Tick() Line 4836 C  [Inline Frame] UE4Editor.exe!EngineTick() Line 62 C  UE4Editor.exe!GuardedMain(const wchar_t * CmdLine) Line 169 C  UE4Editor.exe!WinMain(HINSTANCE_ * hInInstance, HINSTANCE__ * hPrevInstance, char * _formal, int nCmdShow) Line 257 C  [Inline Frame] UE4Editor.exe!invoke_main() Line 102 C  UE4Editor.exe!_scrt_common_main_seh() Line 288 C+  kernel32.dll!BaseThreadInitThunk() Unknown  ntdll.dll!RtlUserThreadStart() Unknown