Crash when destroying a geometry collection actor

UE - Simulation - Physics - Aug 7, 2020

When an actor with geometry collection is destroyed, the engine doesn't remove elements from array in the ChaosSolver So illegal references occurs. Removing element with following quick fix code ...

ISM + WPO = broken motion vectors?

UE - Graphics Features - Nov 5, 2024

Instanced Static Meshes will have incorrect velocity if a Material uses World Position Offset. Fixed WPO in a material causes significant velocity on the ISM. This was also replicated in //UE5/Rele ...

PhysX Crash when spawning Instanced Static Mesh actors at Runtime

UE - Simulation - Physics - Destruction - Oct 13, 2015

Bug generated from crash reporter. This crash has been found in 4.7.6 and still occurs in 4.8.3 and 4.9.2 to users. One user in particular still, and he experiences it often. I have not been able ...

Auto-weld is Enabled even if the blueprint component is set to Simulate

UE - Simulation - Physics - Jan 4, 2017

Auto-weld is Enabled even if the blueprint component is set to Simulate. This only effects blueprint, static mesh actors in the world still disable Auto-weld if set to Simulate. This is a Regressio ...

Consolidate tool fails to replace unloaded references to Material Instances

Tools - Feb 20, 2018

This issue is not a regression, it has been broken since the start of UE4. This bug may be related to [Link Removed] . Per licensee: We are trying to replace certain materials with material instan ...

Invalid GUIDs on new material instance parameters cause overrides to break on base param rename

UE - Rendering Architecture - Materials - Sep 3, 2025

When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...

Landscape Components No Longer Editable after Undoing Component Deletion

UE - LD & Modeling - Terrain - Landscape - Oct 20, 2015

When working in Manage Mode with Landscapes and deleting a component, if you undo the deletion, you can no longer modify or select the component. I did attempt to rebuild the scenes lighting and ge ...

High Res Screenshot Tool Scene Color rendering washed out as EXR

UE - Graphics Features - Dec 8, 2015

When rendering out the Buffer Visualization Targets with the HDR setting on, the resulting Scene Color EXR is rendering significantly washed out compared to the Buffer Viz. in the Editor and if comp ...

Behavior of configuration file hierarchy is different from document

UE - Foundation - Core - Nov 6, 2015

Licensee reported behavior of configuration file hierarchy is different form document here (https://docs.unrealengine.com/latest/INT/Programming/Basics/ConfigurationFiles/index.html) Doc: 1. Engine ...

Python crash the engine at exit.

UE - Editor - Workflow Systems - Oct 25, 2022

A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...