Unreal Lightmass does not build by default when building Solution from Promoted Github 4.12

UE - Foundation - Cpp Tools - UnrealBuildTool - Jan 19, 2016

When building the Promoted 4.12 Solution from Github as of the 4AM commit, the Unreal Lightmass project does not build by default. This results in the inability to build lighting until Unreal Light ...

Opening or Creating a Material with SubSurface Profile will Crash Editor with LPV enabled

UE - Graphics Features - Dec 22, 2014

After enabling Light Propagation Volumes with the console variable r.LightPropogationVolume=1, opening or creating a material with the subsurface profile model will crash the editor. Broken in 4.6. ...

Material Instance Parameter Values Reset When Renamed

UE - Rendering Architecture - Materials - Nov 27, 2017

Per Licensee: We would like to change some of their parameter names, however when renaming a parameter, its value in all of the corresponding material instances resets to the base material default ...

SingleLayerWater with PixelDepthOffset gives wrong refraction

UE - LD & Modeling - Terrain - Water - Oct 29, 2020

We can see refraction gets distorted after we have a bigger PDO value, and it's not because the depth is more shallow, but looks like some kind of scene color texture lookup error. Also, not sure i ...

The GetCombinedForces put out wrong value when the vehicle is reversing

UE - Simulation - Physics - Aug 19, 2022

Reproduced 3/3 times. A similar bug occurred with PhysX ([Link Removed]) Check the function:  FVector FSimpleAerodynamicsSim::GetCombinedForces(float VelocityIn) if the velocityIn is negative, th ...

5.5.3 insights crashes when opening .utrace files with "RenderCommands,RDG,RHICommands" channels.

UE - Foundation - Insights - Feb 19, 2025

The customer provided reproduction steps and a trace file that crashes Insights. From the customer: manually placing if (!CurrentGraph) Unknown macro: { return; } nullchecks in RenderGraphInsi ...

Editor freezes then crashes while attempting to save during PIE

UE - Gameplay - Blueprint - Jun 8, 2015

A level blueprint that has blueprint functions on keybound events freezes and crashes when in PIE and save is pressed. Frequency: 7/7 Crashreporter: [Link Removed] Note: If all level blueprint n ...

AIController.BrainComponent not being set to user-created BehaviorTreeComponent instance

UE - AI - Apr 30, 2015

If a user manually created a UBehaviorTreeComponent for his custom AI controller, but forgets to set AIController.BrainComponent to point at that BT component then a fair amount of assumptions break ...

ForEach 'Enum' node returns incorrect enum values

UE - Gameplay - Blueprint - Aug 21, 2015

ForEach 'Enum' node returns incorrect enum values User Description: The For Each loop and Byte To Enum function return weird things. The same outputs happen with the Byte To Enum, depending on wh ...

RootMotion Malfunctioning When Played in Lower Framerates

UE - Gameplay - Player Movement - May 2, 2016

Root Motion Animations are not functioning correctly during lower frame rates. For example, a character moving forward 2 meters at regular frame rate will move 10 meters at a lower frame rate. Regr ...