-binnedmalloc is broken on Linux

UE - Platform - Linux - Oct 31, 2016

In 4.13 launching a linux game with -binnedmalloc will use the binned allocator. In 4.14 the command line was accidentally changed to -binnedmalloc1 while making other changes. It is still -binnedm ...

CRASH: Editor Crashes When Minimum Value of X Axis Range in 1D Blendspace is not set to Zero

OLD - Anim - Nov 17, 2014

Crash Reporter: [Link Removed] In a Blend Space 1D, setting the minimum value to any variable other than zero then applying and saving results in the editor crashing. Since being labeled "fixed," ...

Using GENERATED_BODY() instead of GENERATED_UINTERFACE_BODY() in an Interface code class results in a UHT crash when trying to build the project.

UE - Foundation - Core - Mar 3, 2015

Replacing GENERATED_UINTERFACE_BODY() with GENERATED_BODY() in 4.7.0 or above results in an Unreal Header Tool crash and build failure in Visual Studio. This was working in 4.6.1, but when tested i ...

Content Examples: Blueprints_Overview Stand 1.7 Spark particle system does not fire from coin

Docs - Samples - Jan 19, 2017

During runtime, the red coin in Stand 1.7 on the Blueprints_Overview map of Content Examples should emit a large spark particle system 5 times. While investigating, I tried disabling "Use Fixed Rel ...

Map load stalls in texture streaming code

UE - Graphics Features - Jun 13, 2017

A change was made to AActor.GetComponents which appends the results instead of resetting the output array. This seems to only impact 2 places in the code, and has a big side effect in the texture st ...

Unimplemented Simplygon function causes empty mesh LODs and crashes

Tools - Aug 31, 2018

When we do the refactor for MeshDescription we miss the staticmesh reduction project settings option and change only the quadric reduction. There are two possible fixes for this issue: 1. Implemen ...

Mobile VR - Render Targets not working with Mobile Multi-View

UE - Platform - XR - Jun 6, 2019

Render target materials display as black on mobile VR when Mobile Multi-View is enabled. Also confirmed with LDR capture source. User also reports issues with scene depth (potentially fixed with [ ...

Overriding Component class does not work properly in grandchild class BP

UE - Framework - Blueprint - Feb 22, 2023

If you set ComponentClass override in child class BP and grandchild class BP respectively, it is ignored in grandchild class. This issue is probably related to [Link Removed] ...

Add Substrate Material Support to Lumen Performance Overview

UE - Rendering - Features - Shading Models - Feb 10, 2025

There is a discrepancy when inspecting Substrate materials in the Lumen Performance Overview. Compared to viewing non-Substrate materials the overview show all surfaces in red indicating that Lumen ...

Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker

UE - Rendering - Graphics Features - Ray Tracing - Dec 12, 2025

If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...