UKismetArrayLibrary::GenericArray_Shuffle is weighted to return some results more than others

UE - Gameplay - Aug 15, 2017

The implementation of UKismetArrayLibrary::GenericArray_Shuffle() will generate certain array shuffle results more often (up to three times as much) than others, rather than having a roughly equal c ...

Descriptions for vis log shapes in the Rewind Debugger are misaligned

UE - AI - Debugging - Mar 25, 2025

When recording shape information, descriptions are offset from the shape. Licensee Message - I noticed that the capsule vis log description labels were not lining up after replaying the recording ...

[Feature Request] FWebBrowserWindow::UnbindUObject of IOSPlatformWebBrowser.cpp is not implemented yet

UE - Platform - Mobile - May 23, 2018

FWebBrowserWindow::UnbindUObject on iOS is not implemented yet.  IOSPlatformWebBrowser void FWebBrowserWindow::BindUObject(const FString& Name, UObject* Object, bool bIsPermanent /*= true*/) { } ...

Crash in FMaterialUtilities::CreateFlattenMaterialInstance when building Simplified HLOD layer

UE - World Creation - Worldbuilding Tools - HLOD - Aug 17, 2022

From licensee: The issue here starts in FVoxelizeMeshMerging::ProxyLOD() where the FlattenMaterial created using FMaterialUtilities::CreateFlattenMaterialWithSettings() returns an empty struct. I d ...

PSO Creation hangs on task in Shipping build

UE - Rendering Architecture - RHI - Nov 27, 2023

Running with `r.AsyncPipelineCompile=0` causes the issue not to happen. It fails to open about 4 times out of 5. No such problem in development build., it always succeeds. We noticed that if we de ...

StreamableManager does not apply CoreRedirects to loaded paths

UE - Framework - Jun 12, 2025

When loading soft object paths directly, it applies any important CoreRedirects by calling the function FixupCoreRedirects if the initial load attempt fails. In the repro steps, this will apply this ...

BP-implemented BT decorators end up thinking they're not on active branch

UE - AI - Mar 13, 2015

This issue makes BP BT decorators not being able to run condition checking every tick. The core issue is here: bool UBTDecorator_BlueprintBase::GetShouldAbort(UBehaviorTreeComponent& OwnerComp) co ...

[CrashReport] UE4Editor_Foliage!FMulticastDelegateBase<FWeakObjectPtr>::CompactInvocationList() [multicastdelegatebase.h:159]

UE - World Creation - Worldbuilding Tools - Foliage - Aug 15, 2017

This is a trending crash coming out of the 4.17 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 150 /** 151 * Removes ...

The Editor will crash on load if a class contains a CanvasRenderTarget2D that is set using CreateCanvasRenderTarget2D.

Tools - Oct 23, 2014

Adding a CanvasRenderTarget2D* UPROPERTY to a class and setting it using CreateCanvasRenderTarget2D will cause the Editor to crash on load. CRASHREPORT: [Link Removed] UDN: This was also reported ...

Failed to generate Nanite data for mesh with bDoFastBuild enabled

UE - Graphics Features - Nanite - Oct 1, 2025

If "bDoFastBuild" is enabled on a Static Mesh asset, in-editor it will never be able to have Nanite data built for it, preventing the Static Mesh from using Nanite. There is no way to fix this issu ...