Ensure triggered when creating Scene Proxy for GroomComponent

UE - Rendering Architecture - RHI - Apr 30, 2025

When a room component is added in C++ via the actor constructor, an ensure is triggered from precaching and the groom component. Behavior also observed on UE5/Release-5.5, CL: 40988944 ...

Crash When Raycasting Against Mesh With Multiple Materials

UE - Simulation - Physics - Feb 26, 2016

When using a raycast trace against a blueprint that has a child component with multiple materials will cause the editor to crash after a few times. This will not be an instant crash, but requires th ...

Creating multiple Scalar Parameter nodes with a different values will crash the editor

UE - Rendering Architecture - Materials - Mar 11, 2020

This is a regression from 4.24.3 CL 11590370 This was discovered when ad-hoc from home I ran into this by running this set up https://docs.unrealengine.com/en-US/Engine/Rendering/Materials/HowTo/Cle ...

Invalid access location compressing a BC6h texture in the editor

RAD - Oct 29, 2024

Large texture crashes during Oodle compression with "-stompmalloc". It appears to be an internal Oodle error. Also tested on //UE5/Release-5.5/, CL: 37463908 ...

Bug in StringTemplate.cpp related to modulo operator in MaterialTemplate.ush (code fix provided)

UE - Rendering Architecture - Materials - Jun 25, 2024

Shader Template files like MaterialTemplate.ush do not submit previous chunks when encountering a `%` character, unless that `%` character is `%s` or `% {...} `. Because the error is happening ...

ResavePackages commandlet (buildlighting) fails/asserts on reflection captures in non-visible sub-levels

UE - Graphics Features - May 13, 2025

When building reflection captures through the ResavePackages commandlet, it frequently triggers an ensure inside of ReflectionEnvironmentCapture.cpp. If distributed shader builds start causing prob ...

Control Rig settings are not retained between editor sessions or carried into deployed game

UE - Anim - Rigging - Control Rig - Jun 10, 2020

Control Rig settings are not retained between editor sessions or carried into deployed game ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

MakeArray wildcard node gives a compilation error when being used in a Blueprint Macro.

UE - Framework - Blueprint - Dec 19, 2024

There is an error with the SmartMacroInterface, where you can't use an empty wildcard "Make Array" node. This error makes the blueprint not compile and the macro unusable. Disabling the bUseSimpleWi ...

Crash occurs when diffing blueprint that has had one of its variables changed to a Soft Object Reference

UE - Gameplay - Blueprint Editor - Oct 3, 2017

A crash occurs when diffing a blueprint that contains an array that has changed from an Object Reference to a Soft Object Reference. Note: I figured that this could be related to another bug that I ...