Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location

UE - Simulation - Visual - Jun 22, 2025

Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location. When that flag is true, the moment the GeometryCollection (GC) ...

Possible incorrect pointer manipulation in BeginPackageCacheForCookedPlatformData

UE - Foundation - Core - Cooker - Dec 12, 2017

In UCookOnTheFlyServer::BeginPackageCacheForCookedPlatformData(), there is a pointer to int32 called CurrentAsyncCache that is used as an index. It's value is dereferenced before it is checked, but ...

Editing parent emitters with mesh renderer in a niagara system causes crash

UE - Niagara - Nov 9, 2021

After editing the parent emitters of a Niagara system with mesh renderer particles the engine will crash the next time the editor and system are opened.  This was tested with both engine content cub ...

Unable to build marketplace code plug-in

UE - Foundation - Cpp Tools - UnrealBuildTool - May 17, 2022

Fix for [Link Removed] sets the RuleAssembly in the Marketplace plugin to ReadOnly. This has prevented the plugin binaries from being compiled. Change the readonly flag as shown in the following co ...

When using Perforce, saving a level over another leaves the target umap file as "marked for delete"

UE - Editor - Workflow Systems - Mar 11, 2025

When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...

[CrashReport] UE4Editor_Engine!FShaderCompilingManager::LaunchWorker() [shadercompiler.cpp:1573]

UE - Graphics Features - Aug 21, 2017

This is a common and longstanding crash that has occurred since at least 4.9. The issue appears to be due to missing ShaderCompileWorker.exe in binaries, but many of these crashes occur in the vani ...

DataTable asset view runs out of (video) memory

UE - Editor - UI Systems - Slate - Feb 26, 2024

In some situation, Slate tries to secure incredible amount size data and run out of memory. This happens a cell having very long and complex serialized text appears on the editor and it is placed to ...

Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor

UE - Anim - Anim in Engine - Jul 15, 2025

Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...

Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA

UE - Graphics Features - Feb 5, 2025

There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...

Crash rendering image sequence if the Sub-Level with matinee is not loaded

Tools - Apr 15, 2016

Crash rendering image sequence if the Sub-Level containing the matinee is not loaded. This seems to go away if the level is either set to "Always Loaded". Seems to be a result of people not switch ...