Investigate intermittent crash in CacheOptimizeIndexBuffer on Editor startup on Linux

UE - Platform - Linux - Nov 23, 2015

Building 4.10 from the GitHub release branch on Linux fails to open after install and instead crashes Community Suggested Fix: Switching triangle order optimization off with r.TriangleOrderOptimiza ...

Particle Bounds Don't Update Correctly After Moving Particle Component Via BP

UE - Graphics Features - Mar 30, 2017

It appears that particle components don't update their bounds correctly when they are moved in a scene. If a particle emitter isn't currently visible at the start of the game it will remain culled. ...

Reimporting Static Mesh LODs yields unexpected material assignments

Tools - May 24, 2018

Reimporting an asset after making changes causes loss of saved LOD changes when editing a static mesh. Similar issue was logged and fixed for SkeletalMeshes but this issue is still occurring for ...

Non-nativized classes that implement a nativized interface class do not get interface methods called when invoked through a Blueprint function library.

UE - Gameplay - Blueprint - Jul 5, 2018

UObjectBaseUtility::GetInterfaceAddress() fails due to an incorrect serialized value of the 'bImplementedByK2' property within the non-nativized class's Interfaces array on save. See support thread ...

HLOD visibility state isn't cleared when changing scene

UE - Graphics Features - Sep 25, 2018

HLOD state is not cleared when moving to a scene without HLOD so primitives may read the state from the old scene and incorrectly cull objects. The safe fix is to clear the HLOD state maps when the ...

Calling TearOff then Destroy on an actor results in client actor also being destroyed

UE - Networking - Jan 14, 2021

When calling TearOff followed immediately by Destroy, the channel will be closed with the reason that the actor was destroyed, so the actor will be destroyed on the client as well. In the UDN linke ...

Renaming a SkinnedMeshComponent onto a different owning actor will cause issues with FAnimUpdateRateManager

UE - Anim - Runtime - Aug 12, 2021

As mentioned in the UDN - the user tried to rename an SMC to a different actor, which leaves the URO manager left with an incorrect data as it is not aware of the move. User proposed overriding Post ...

Reimporting static mesh doesn't respect changed lightmap settings

UE - Editor - Content Pipeline - Import and Export - May 11, 2023

Licensee reports change of behaviour between UE4 and UE5 when reimporting a mesh after changing its lightmap build settings. Change of behaviour occurred in 17404767, which was to fix a similar pro ...

Material Layers "swap" location instead of shift downwards.

UE - Rendering Architecture - Materials - Oct 17, 2023

Licensee request for this as it is affecting productivity. Likely requires a method of allowing a user to choose which behaviour they prefer. For reference, the behaviour changed in CL 11684461 to f ...

External Actors can hold stale references to Blueprint classes as edited instance properties

UE - World Creation - Worldbuilding Tools - Nov 14, 2024

When a component is removed from a class that exists as an instance with external actors enabled, a deleted BP component on an actor will remain referenced by the instance. Disabling External Actor ...