TMap where key is an FString: initializer list will accept bad MakeTuple

UE - Core - Systems - Sep 2, 2026

POST LINK: https://forums.unrealengine.com/t/tmap-where-key-is-an-fstring-initializer-list-will-accept-bad-maketuple/2747443 POST BODY:Summary A TMap where the key is an FString can be created lik ...

[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 - Runtime - Animation - 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 - Runtime - Simulation - 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

zComponent - Archive - 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 ...