Duplicating many Actors at once in a Level Instance while in Level Instance Edit will result in a jumbled mess of Actors on the Persistent Level

UE - World Creation - Worldbuilding Tools - Level Instances - Feb 12, 2025

Duplicating many Actors at once in a Level Instance while in Level Instance Edit will result in a jumbled mess of Actors on the Persistent Level. The licensee has encountered this in Unreal 5.4 and ...

Ensure triggered upon improper math expression

UE - Gameplay - Blueprint - Aug 4, 2016

An ensure is triggered upon entering an improper math expression. ...

After importing morph target: Ensure condition failed: Referencing SkeletalRenderGPUSkin.cpp

Tools - Sep 23, 2017

Hit handled ensure when dragging the slider in Morph Target PreviewLogOutputDevice: Error: Ensure condition failed: DynamicData->MorphTargetWeights.Num() == LODModel.MorphTargetVertexInfoBuffers.Get ...

ACineCameraAttachMount's "Target Actor" constraint does not work with Spawnables or Replaceables in Sequencer

UE - Virtual Production - Tools - Virtual Camera - Aug 12, 2025

Constraints (UTickableConstraint) are usually created throuh the "Animation" tab available in the Editor's "Animation Mode". When created through that interface while Sequencer is open, the internal ...

VR Preview crash when shadow quality is set to low

UE - Platform - XR - Dec 5, 2024

[/Script/Engine.RendererSettings] r.Tonemapper.Sharpen=2 r.TemporalAA.Upsampling=False r.DefaultFeature.AutoExposure.ExtendDefaultLuminanceRange=True r.LightPropagationVolume=0 r.ReflectionCaptureRe ...

EQS Overlap test no longer recognizes custom Collision Object Channel

UE - AI - Nov 12, 2019

Environment Queries Ignore tests for Custom Collision Object Overlaps. Note: The expected behavior seems to have worked in 4.21, After following the steps to reproduce, I can verify a successful de ...

Hardware Raytracing on Lumen can cause a crash on AMD Radeon GPUs

UE - Graphics Features - Lumen - Jul 29, 2025

Hardware Raytracing support can cause a crash on AMD Radeon GPUs when creating the RT pipeline state. ...

Certain UPROPERTY values are not updated during auto-recompile

UE - Gameplay - Blueprint - Aug 4, 2016

Sometimes manual recompile is required to make a blueprint actually recompile data-only changes, but not always. If the last manual compile was with default values, then changes are not updated. If ...

Physics Asset ignoring Root Bone Rotation collision in Skeletal Mesh.

UE - Simulation - Physics - Dec 20, 2018

**Physics collision ignores Capsule Collision, When Skeletal mesh root bone orientation is rotated in the Z-Axis, resulting in unexpected collision behavior.   Screen shot has been attached to de ...

UE5.6+ - Mutable - IDPrefix crash when combining Child Objects, Add to Mesh Component and Extend Mesh Section.

UE - Anim - Mutable - Jul 21, 2025

So the issue seems to be a combination of Add To Mesh Component and Extend Mesh Section. I've tried this in Epic Launcher 5.6, 5.6 in-house modified engine as well as ue5-main 5.7 from git (editor ...