Paper2D performance regression due to TArray resizing

UE - Graphics Features - Aug 16, 2019

We've noticed after upgrading our heavy Paper2D project to 4.22 that tilemap performance has been massively degraded compared to previous versions. After some digging we found out that it's due to a ...

It is possible to rename a Function Output the same as a Local Variable, which causes a compile error

UE - Gameplay - Blueprint - Apr 15, 2015

It is possible to rename a Function Output the same as a Local Variable, which causes a compile error: Error Internal Compiler Error: Tried to create a property TestVar in scope NewFunction_0, but ...

[CrashReport] Mac Crash - UE4Editor-Engine.dylib!LoadPhysXModules(bool)::$_0::operator()()

UE - Platform - Apple - Aug 15, 2017

This is a trending Mac crash coming out of the 4.17.0 release. It appears to occur before users are able to open their project. I have not found any records of this crash occurring on Windows. Use ...

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 ...

Crash can occur when calling GetSkinnedVertexPosition on a skeletal mesh with a slightly different bone hierarchy than the skeletal mesh whose skeleton it is using

OLD - Anim - Apr 12, 2017

MDW: In progress (Dev-AnimPhys CL 3392820) When calling GetSkinnedVertexPosition on a skeletal mesh that uses the same skeleton as a different skeletal mesh with a slightly different bone hierarchy ...

[CrashReport] UE4Editor_Engine!UModelComponent::CommitSurfaces() [modelcomponent.cpp:163]

UE - LD & Modeling - Modeling Tools - BSP - Oct 26, 2017

This is a somewhat common crash that has existed since at least 4.14.. It appears related to an Undo operation on geometry. User DescriptionsUndoing a move of a boxbrush wall and staircaseundoing i ...

Error maximum ps_5_0 sampler register index (16) exceeded on some materials in InfiltratorForward

UE - Graphics Features - Dec 13, 2016

Certain materials no longer compile in InfiltratorForward with Forward Shading enabled. These materials were not having this compile issue in //UE4/Main @ CL - 3231640 which is the CL before Dev-Ren ...

[CrashReport] UE4Editor_Landscape!FLandscapeSplinesSceneProxy::GetDynamicMeshElements() [landscapesplines.cpp:159]

UE - LD & Modeling - Terrain - Landscape - Nov 17, 2017

This is an infrequent crash in 4.18. Users have not provided any descriptions of their actions when the crash occurred. Source Context 147 for (int32 ViewIndex = 0; ViewIndex < Views.Num( ...

[CrashReport] UE4Editor_D3D11RHI!TerminateOnDeviceRemoved() [d3d11util.cpp:176]

UE - Graphics Features - Nov 18, 2016

Error message: Fatal error: [Link Removed] [Line: 176] Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - 'HUNG') Source Context: 161 162 const TCHAR* Rea ...

[CrashReport] UE4Editor_SlateRHIRenderer!FSlateRHIResourceManager::GetShaderResource() [slaterhiresourcemanager.cpp:525]

UE - Editor - UI Systems - Slate - 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. Jiras for similar callstacks in ...