Unreal Engine Issues
Unreal Engine Issues
Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances
UE - Rendering - Graphics Features - Ray Tracing - May 28, 2026When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...
Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI
UE - Simulation - Visual - Apr 22, 2025Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI. The licensee noticed that the Trailing event is not available to BPs. It's expected that the same data avail ...
Editor crash when a spline component is added to a blueprint and compiled
Tools - Sep 7, 2016Most recent user affected CL: 3106830 (4.13.0) Error message: Access violation - code c0000005 (first/second chance not available) Source Context: SelectedKeys = SplineVisualizer->GetSelectedKey ...
[CrashReport] UE4Editor_D3D11RHI!TerminateOnDeviceRemoved() [d3d11util.cpp:176]
UE - Graphics Features - Nov 18, 2016Error message: Fatal error: [Link Removed] [Line: 176] Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - 'HUNG') Source Context: 161 162 const TCHAR* Rea ...
Editor Utility Widgets: Asset creating nodes' output pins in uber graphs cause asset deletion warning
UE - Framework - Blueprint Runtime - Oct 8, 2024Editor Utility Widgets (EUW) can be used to script editor behavior. One use case is the automation of asset creation. A licensee has reported that when an EUW is used to create an asset, for as lon ...
FKeyHandle internal static atomic counter can overflow on long running games depending on usage pattern
UE - Anim - Sep 24, 2025Structure FKeyHandle stores an internal index, which is initialized from a static atomic counter in the default constructor: +----- FKeyHandle::FKeyHandle() { | static std::atomic<uint32> LastKey ...
Compilation errors with UE_NET_ENABLE_REPLICATIONREADER_LOG enabled
UE - Networking - Iris - Jul 15, 2024Enabling UE_NET_ENABLE_REPLICATIONREADER_LOG results in the following errors: {{4>[1/5] Compile [x64] ReplicationReader.cpp 4>D:\P4V\UE5-Main\Engine\Source\Runtime\Experimental\Iris\Core\Private\Ir ...
Custom UVs don't store information properly in layered materials.
UE - Rendering - Architecture - Materials - May 9, 2022[Link Removed] I have this set up so that FX artists can stack UV manipulations, so I don't want to just have all the UV manipulation in the layer with the base color, even though that does give me ...
Assertion failed in FAudioDevice::UnregisterSoundClass when GC
UE - Audio - Aug 13, 2018The licensee reported that check(IsInAudioThread()) was failed in FAudioDevice::UnregisterSoundClass when GC. The following is the call stack: 1 #00 pc 030d7b58 libUE4.so HandleError (/home/pirates ...
5.5 Static Mesh Import Pipeline Regression
UE - Editor - Content Pipeline - Import and Export - Apr 25, 2025This question was created in reference to: [Link Removed] This post references the first post because this problem was not discovered till now. I think it was masked because the issue appears to be ...