Niagara system loses source emitters when moving Engine from 4.22 or earlier to 4.23 or later.

UE - Niagara - Nov 29, 2019

The following code causes this behavior.// NiagaraSystem.cpp for (FNiagaraEmitterHandle& EmitterHandle : EmitterHandles) { EmitterHandle.ConditionalPostLoad(NiagaraVer); if (!EmitterHandl ...

Problems in skeletal mesh merge

UE - Editor - Content Pipeline - Asset Build - May 10, 2021

There are a few issues a licensee has found with the skeletal mesh merge operation. See the UDN for more details and the proposed fixes. Note, the issue with the cloth merge is already logged in a ...

bIgnoreAllPressedKeysUntilRelease only applies to keys in the previous mapping

UE - Gameplay - Input - Jun 16, 2022

This is because the RebuildControlMappings function only checks this flag when you have a mapping that was already added, we should apply this for any new mappings as well.  I'll update the repro s ...

Disabling bLerpUVs in Nanite Settings of Static Mesh causes texture warping in clusters

UE - Graphics Features - Nanite - Jan 21, 2025

The licensee has identified a potential fix by changing if( Settings.bLerpUVs ) to if( Settings.bLerpUVs || UVIndex == 0 ) On line 389 of NaniteBuilder\Private\Cluster.cpp in UE 5.5 ...

Crash opening levels with landscape in them via the command console in standalone game

UE - LD & Modeling - Terrain - Landscape - Aug 8, 2016

Standalone game is crashing when opening certain maps using the command console. Crashed QA-Promotion QA-Landscape TM-VRSmoke No Crash QA-Decals QAEntry ...

Editor crash when adding a spline component after having deleted another spline component

UE - Gameplay - Sep 26, 2016

After adding a duplicate spline point, removing the spline component while the duplicated point is selected and creating a new spline in its place causes the editor to crash. Crash Reporter: [Link ...

Crash Occurs When Using Invalid HideCategories

UE - Gameplay - Blueprint - Aug 8, 2016

The licensee is experiencing a crash when using UCLASS(HideCategories = (Activation, LOD, Collision, Rendering, TextureStreaming, Lighting, Mobile, Transform, Physics, Tags)) This crash occurs afte ...

Float Curve that is set as a local variable in an actor's function is garbage collected when in Standalone, causing a crash

UE - Gameplay - Blueprint - Sep 9, 2016

If a Curve Float local variable is created for a function, it will be garbage collected when garbage collection occurs. This causes the process to crash due to an null pointer error whenever it is r ...

Editor crashes when copying a copied instance of a blueprint in the level.

UE - Gameplay - Blueprint - Aug 9, 2016

Editor is crashing when copying a copied instance of a blueprint in the level. We were unable to reproduce this issue adding a component to the blueprint through the blueprint editor. This issue on ...

Standalone window played from editor hits assert Index >= 0 in UObjectArray

UE - Gameplay - Blueprint - Sep 23, 2016

Standalone window in editor will hit assert in a bit of time. Issue doesn't happen is playing standalone via Visual Studio. ...