Crash when using "Convert to Variable Curve"

OLD - Anim - Jun 7, 2016

Error message: Access violation - code c0000005 (first/second chance not available) Source Context: 7 8 DECLARE_CYCLE_STAT(TEXT("AnimSeq EvalCurveData"), STAT_AnimSeq_EvalCurv ...

Orientation Warping breaks incoming poses where bones are in component space

UE - Anim - Gameplay - Apr 17, 2025

The orientation warping node breaks incoming poses where bones are already in component space. This is because, in EvaluateSkeletalControl_AnyThread, we are repeatedly setting bone transforms direc ...

Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor

UE - World Creation - Worldbuilding Tools - World Partition - Dec 18, 2025

Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor. As described in the steps to reproduce, if we keep swapping bIsSpatiallyLoaded state and save a Streaming Level ...

Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine

UE - Anim - Jan 22, 2026

Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine with a "Cannot replace existing object of a different class" message. The conditions to re ...

Assert crash when playing Groom Cache with Card Mesh LOD

UE - Rendering - Graphics Features - May 29, 2026

Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...

Moving all the related assets to another folder at once leads to reference lost in the contents browser.

UE - Editor - Content Pipeline - Content Browser - Aug 23, 2017

Moving all the related assets into another folder leads to reference lost. This can be tested out using ShooterGame project. Also you can find materials in the skeletal mesh lost its texture. This ...

[CrashReport] FPhysicsAssetEditorSharedData::FPhysicsAssetEditorSharedData

UE - Simulation - Physics - Nov 2, 2017

This is a trending crash coming out of the 4.18 release, and may be a regression. Users have not provided any descriptions of their actions when the crash occurred. Source Context 2290 #end ...

Loading a blueprint with an invalid gameplay tag container pin causes ensure and data loss

UE - Gameplay - Feb 23, 2021

The gameplay tag system depends on tags being registered with the global manager as valid in order to correctly read them off disk. Two different issues are combining to cause a confusing ensure and ...

Chaos : Rigid body sleeps when very small external force is applied by AddForce

UE - Simulation - Core - May 25, 2022

When a small external force is applied to the rigid body, the VSmooth value is reset in the ResetVSmoothFromForces function. Since this function ignores the current velocity, a very small velocity ...

Widgets will bind input delegates to the Player Controller's Input Component, but never unbind them

UE - Editor - UI Systems - UMG - Jan 30, 2024

This is a bug introduced with 18468289 a while ago. We added this functionality for [Link Removed], which allows input event nodes to be placed within widgets and have them behave correctly.  This ...