Unreal Engine Issues
Unreal Engine Issues
ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision
UE - Simulation - Physics - Jan 27, 2025ensure(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, 2016This 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
UE - Anim - Sequencer - Nov 15, 2025When 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 ...
Changing MaterialQualityLevel causes a crash due to a ShaderMap mismatch in UniformExpressionCache
UE - Rendering Architecture - Materials - Nov 26, 2025A crash may occur when changing the MaterialQualitylevel via Scalability due to a race condition. The issue occurs because in ScalabilityCVarsSinkCallback(), when it creates the FGlobalComponentRec ...
GAS: Mixed replication mode and error in MinimalReplicationTags code
UE - Gameplay - Gameplay Ability System - Apr 6, 2022We'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, 2017This 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 ...
[CrashReport] UE4Editor_Engine!FMaterialShaderMap::GetMeshShaderMap() [materialshader.cpp:2395]
UE - Graphics Features - Mar 30, 2018User 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, 2016I 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. ...
MotionWarping does not recognize new MontageInstance with the same montage
UE - Anim - Gameplay - Jan 11, 2023When the same AnimMonotage is played again while moving with MotionWarping & RootMotion, UAnimNotifyState_MotionWarping does not recognize it. From licensee: The issue was that in URootMotionMod ...
Exception on missing file during GC in horde storage
UE - Foundation - Horde - Storage - May 7, 2025During GC, if a file was manually deleted (but the storage system is still track), GC can erroneously fail (and never remove the reference). This causes a backup in GC, putting the whole algorithm i ...