Movie Scene Capture - DX12 Render Artifacts and Delay

UE - Rendering Architecture - RHI - Jun 19, 2023

If using the Legacy renderer (Movie Scene Capture) with DefaultRHI DirectX12, there's new delay and also some frames get weird artifacts.   However, the delay and artifacts do not appear when using ...

Soft angular constraints solve velocity like hard constraints

UE - Simulation - Physics - Jul 17, 2025

Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...

Packaged Game Crashes When Launched with the -dx12 for Ray Tracing Features and PixelStreaming enabled

PixelStreaming - Apr 3, 2019

Packaged game crashes when launched with the -dx12 option and PixelStreaming is enabled. Found in 4.22 CL# 5660361 and 4.23 CL# 5704223 ...

Setting NavModifierVolume's AreaClass at runtime does not result in navmesh rebuilding

UE - AI - Apr 23, 2015

The volume does accept the change and if it gets moved the navmesh will rebuild with new area set. The core issue is that setting NavModifierVolume.AreaClass at runtime does not notify navigation sy ...

[CrashReport] UObjectBaseUtility::GetOutermost | FArchiveInvalidateTransientRefs::operator<<

UE - Gameplay - Blueprint - Sep 7, 2017

This is a somewhat common crash affecting users in 4.17. They have not provided any descriptions of their actions when the crash occurred. Source Context 110 /** 111 * Walks up ...

Cannot specify custom window positions in "windowed mode" for packaged games

Tools - Nov 30, 2017

There is an issue where you cannot specify a specific location for a windowed packaged game when using a command line to open the project, the project will move to that position for a brief moment b ...

Static mesh's material slot's cast shadow does not require a build of StaticLight

UE - Graphics Features - Dec 7, 2017

If static mesh's material slot's cast shadow is changed, UE4 does not show "LIGHTING NEEDS TO BE REBUILT". I solved it with the following fixes. StaticMeshEditorTools.cpp void FMeshSectionSettin ...

Cannot run any packaged project if "Force all skinned meshes to recompute tangents" has been enabled in an unrelated project

UE - Foundation - Core - Apr 20, 2018

Enabling the "Force all skinned meshes to recompute tangents" sets the value at a Windows user level so that it affects all UE4 projects opened by that user, including unrelated packaged projects. T ...

Nativizing actor does not destroy component with construction script.

UE - Gameplay - Blueprint Compiler - Nov 19, 2018

Running destroy component with construction script placed on level blueprint does not destroy component when it is nativized. It works correctly with PIE and Not Nativize. Also, if the actor that wa ...

Undo then Redo Creating a Spawnable in Sequencer Creates Extra Actor in Level

UE - Anim - Sequencer - May 3, 2023

There is a bug when performing an undo/redo on pasted or spawned actors in Sequencer.  It appears that the transaction system is re-creating an actor on redo, but Sequencer doesn't see that, so it ...