Crash opening Soul City in 4.19

UE - LD & Modeling - Terrain - Landscape - Mar 15, 2018

This does not reproduce in 4.18.2 I spoke with Tim G. from the tools team and we tried a few things. 1stOpened LV_Soul_Slum in 4.18Exported the landscape height mapOpened a level in 4.19 and impor ...

Previewing Node in Material Editor Produces Unexpected Output with DX12

UE - Graphics Features - May 16, 2018

Per Licensee: Since we switched to DX12 we started to see strange behavior in material previews. I was able to reproduce the problem in UE 4.19 vanilla as well. We usually have to force recompilin ...

Niagara Vector Field CPU access Error prevents its use in projects

UE - Niagara - Jan 31, 2020

Niagara VectorFields do not function properly since "Fix CPU Access" changes are not persistently saved. After every Editor restart or reopening projects, the Niagara-VectorField driven Emitter and ...

Undo function breaks local variables in Blueprint Function after compiling

UE - Gameplay - Oct 8, 2020

Blueprint functions appear to correctly associate local variables when renaming the function. However when undoing a rename with ctrl-z the local variables appear to lose their association. Redoing ...

FCableSceneProxy::BuildCableMesh thrashes memory allocator

UE - Runtime - Simulation - Feb 12, 2025

FCableSceneProxy::BuildCableMesh in CableComponent.cpp:233 showed up as a hot spot in profiling because the two TArray allocators in SetDynamicData_RenderThread used by BuildCableMesh are created an ...

Particle Random Value is the same for all particles with a Niagara Mesh Renderer

UE - Rendering - Architecture - Niagara - Sep 28, 2026

A material using the Particle Random Value node returns the same value for every particle drawn by a Niagara Mesh Renderer. Particle transforms are not affected, only the random value. This happens ...

Widget causing ensure to trigger on end play

UE - Editor - UI Systems - Nov 15, 2019

Widget is causing an ensure to be hit when exiting gameplay.  Tested in: 4.24 Preview2 CL#10091930 , 4.25 CL#10183780 Attached URL's from the user:  https://forums.unrealengine.com/community/ge ...

A Behavior Tree reference to a Blackboard Key will become invalid when the name of the Key is changed in the Blackboard

UE - AI - Oct 5, 2015

A Behavior Tree reference to a Blackboard Key will become invalid when the name of the Key is changed in the Blackboard. Clicking on the Behavior Tree node that references the key will update the ke ...

Overridden functions in Child Blueprints cannot be converted to/from pure functions

UE - Gameplay - Blueprint - Jun 27, 2015

Overridden functions in Child Blueprints cannot be converted to/from pure functions. Reproduced in 4.8.1 and Main (//depot/UE4/Promotable-CL-2601051) ...

Instanced sub-object property values get out of sync between parent and child Blueprints

UE - Gameplay - Blueprint - Jun 17, 2016

Also, another, possibly related symptom that should be looked into alongside this: Possibly related: 1. Set InlineObject to null on both character. 2. Assign new Inline Object to InlineObject on Ba ...