Cloth environment collisions with APEX clothing is not thread safe.

UE - Simulation - Physics - Character - Jan 17, 2017

This looks like a thread safety bug that's been in the clothing system for a very long time. Essentially a skeletal mesh component does a transform update and attempts to update the collisions of a ...

[CrashReport] UE4Editor_Core!TArray<wchar_t,FDefaultAllocator>::operator=() [array.h:396]

Tools - Nov 21, 2017

This is a common crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. The callstack seems to be the same as [Link Removed], which ...

Importing through Python fails

UE - Editor - Content Pipeline - Import and Export - Feb 20, 2019

Version 4.21:The script result in popping the Alembic Import windows instead of a silent importThe provided options are ignored by the importer.  Version 4.22: Results in the provided callstack wi ...

SetNiagaraStaticMeshComponent in UNiagaraFunctionLibrary does not add NiagaraVariable to InstanceParameterOverrides

UE - Niagara - Jan 13, 2023

The result of the Set Niagara Static Mesh Component (OverrideSystemUserVariableStaticMeshComponent) function provided by the UNiagaraFunctionLibrary is different from the operation result on the det ...

Camera View Transformations in Editor and Sequencer Cannot Be Undo (Ctrl+Z)

zComponent - Archive - May 26, 2025

Camera View Transformations in Editor and Sequencer Cannot Be Undo (Ctrl+Z) ​​Description​​: When switching the viewport to a specific camera actor, any manual movement/rotation of the camera (via ...

When Sequencer's Add Filter Menu>Keyed(U) is enabled, adding a Key to an actor that previously failed the Filter (had zero Keys) does not immediately include the Keyed actor in the filtered list (if fails FSequencerTrackFilter_Keyed::PassesFilter)

zComponent - Archive - Jun 25, 2025

When Sequencer's Add Filter Menu>Keyed(U) is enabled, adding a Key to an actor that previously failed the Filter (had zero Keys) does not immediately include the Keyed actor in the filtered list (if ...

DataAsset blueprints have the wrong NativeClass

UE - Gameplay - Nov 18, 2025

UDataAsset's constructor assumes itself to be the native class, and caches that value for use by the asset registry. However, if the data asset type is defined in a blueprint (i.e. subclassing UPrim ...

Instanced Actors: Editor preview don't show correct relative mesh transforms

UE - Engine Scaling - Mass - May 30, 2026

Context Actors can be converted into Instanced Actors via the IA plugin. During runtime and in the editor, an instanced actor’s visual is generated from the collection of StaticMeshComponents on th ...

Setting Simulate Physics breaks "Get Closest Point on Collision" node

UE - Simulation - Physics - Dec 5, 2016

'Get Closest Point on Collision" node is used to determine the distance between a primitive component (target) and another specified location (Point) as well as provide the point on the target. Thi ...

Incorrect physics interaction on rotated meshes using Complex as Simple collision

OLD - Anim - Feb 13, 2017

Incorrect physics interaction on rotated meshes using Complex as Simple collision. *This is a regression Working in 4.13.2-3172292 Not working in 4.14.3-3249277* User Description: When we updat ...