Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI

UE - Simulation - Visual - Apr 22, 2025

Chaos 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 ...

[Feature Request] Cook in the Editor should only save Asset Registry for the cook target platform

UE - Foundation - Core - Cooker - Jan 18, 2018

Request from Licensee: When launch Launching in the editor, it seems that asset registries of platforms other than those specified in Launch are also generated.  LogAssetRegistryGenerator: Startin ...

FKeyHandle internal static atomic counter can overflow on long running games depending on usage pattern

UE - Anim - Sep 24, 2025

Structure FKeyHandle stores an internal index, which is initialized from a static atomic counter in the default constructor: +----- FKeyHandle::FKeyHandle() { | static std::atomic<uint32> LastKey ...

Hot reload causes placed actor to lose variable references

UE - Foundation - Cpp Tools - Hot Reload - Nov 9, 2017

Preforming a hot reload causes placed actors to lose code based variable settings. More repro steps: 1. Open UE4Editor.exe 2. Create a First Person Code project 3. Build the project for Developme ...

Compilation errors with UE_NET_ENABLE_REPLICATIONREADER_LOG enabled

UE - Networking - Iris - Jul 15, 2024

Enabling 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 ...

[CrashReport] Assertion on in UMaterialInterface::InitDefaultMaterials()

UE - Graphics Features - Jun 28, 2017

This is a common Mac crash occurring in the 4.16.1 release. I have not found any evidence of it occurring on Windows. The callstack closely matches [Link Removed], which was briefly experienced by ...

Crashes after destroying a skeletal mesh attached via socket name (not bone name), the destroyed mesh remains welded.

UE - Simulation - Core - Jul 18, 2025

On welding physics bodies during primitive component attachment, UPrimitiveComponent::WeldToImplementation() calls GetRootWelded() and then GetBodyInstance() on the returned root. This searches by b ...

[CrashReport] Crash occurring in Phonon::FPhononReverb::ProcessMixedAudio

UE - Audio - Apr 27, 2017

This is an early trending crash coming out of the 4.16 Preview. Users have not provided any additional information. From Log:/Game/VirtualRealityBP/Maps/UEDPIE_0_StartupMap.StartupMap (0.006787s) ...

[CrashReport] Mac crash - UE4Editor-SlateCore.dylib!FSlateApplicationBase::Get()

UE - Platform - Apple - Oct 5, 2017

This is a slightly common Mac crash that has occurred since 4.17.1. Users have not provided any descriptions of their actions when the crash occurred. Callstack from Log[2017.10.05-15.00.31:683][3 ...

GeneSplicerModule has linking errors in a Development target

MetaHuman - Oct 16, 2025

The FArchiveMemoryStream class is defined in GeneSplicerModule and RigLogicModule. This generate linker error as this doesn't respect the "One Definition Rule"  1>Module.GeneSplicerModule.cpp.ob ...