Morph target is not applied on the first frame in Level Sequence

UE - CAPT - Control Rig - Dec 4, 2025

When a skeletal mesh with morph targets spawns in the sequence, the morph is not reflected in the first frame.  In the ProcessStage_SkinCache call of SkeletalMesh, MorphVertexBuffer->SectionIds is ...

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision

UE - Runtime - Simulation - Jan 27, 2025

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...

[CrashReport] UE4Editor_Renderer!FGlobalShader::SetParameters<FRHIPixelShader * __ptr64,FRHICommandList>() [globalshader.h:134]

UE - Graphics Features - Jun 29, 2016

This JIRA was created from crash reports submitted by users due to it being one of the top crashes occurring in 4.12.4 This might be a regression because the crash has only just started in 4.12.4. ...

Sequencer causes 3DWidget on BP vectors to snap to Actor when active

zComponent - Archive - Nov 15, 2025

When we have Vectors in BP with Show 3D Widget enabled, the Transform Widget would always snap back to the Actor after we move the 3D Widget in-world. [Link Removed] Removing the _DaySequenceActor ...

GAS: Mixed replication mode and error in MinimalReplicationTags code

UE - Gameplay - Gameplay Ability System - Apr 6, 2022

We're on 4.25.4. We recently turned on mixed mode replication for GAS, which seems to work fine and reduce bandwidth as expected. However one of our unit tests started failing with this error messag ...

[CrashReport] UE4Editor_UnrealEd!UFbxSceneImportFactory::ImportOneSkeletalMesh() [fbxsceneimportfactory.cpp:2017]

Tools - Nov 10, 2017

This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 2014 USkeletalMesh *ImportedSkelMes ...

Exporting and Importing Alembic File from Maya to Unreal Adds Extra Frame to Animation

UE - Editor - Content Pipeline - Import and Export - Jan 5, 2018

When importing an Alembic file into Unreal Engine an extra frame is added automatically to the frame range in the import settings -abc file has been brought into Maya 2016 and exported again as an ...

[CrashReport] UE4Editor_Engine!FMaterialShaderMap::GetMeshShaderMap() [materialshader.cpp:2395]

UE - Graphics Features - Mar 30, 2018

User comments in crash group:Duplicating material and switched it cause i have to use itChanging a landscape material.I just import World Machine landscape with multi-layered.Crash when reaching 16 ...

Composite font uses a sub-font, even when the sub-font doesn't support the character

Tools - Apr 7, 2016

I have a fix for this shelved in CL# 2937344, so it would be good to get it into 4.12 once the user verifies the fix. ...

Editor crashes when creating a new level while the current level contains an Actor with an Actor Sequence Component

zComponent - Archive - Jan 5, 2022

This is not a regression. Tested in: //UE5/Main CL18218925 Binary - Crashed //UE5/Release-5.0 CL16682836 Binary - Crashed //UE4/Release-4.27 CL Binary - Crashed Having a level open that contains a ...