Skeletal Meshes with imported LODs will use the highest LOD when generating Nanite, rather than LOD0

UE - Graphics Features - Nanite - Jan 14, 2025

In the SkeletalMeshBuilder, Nanite is generated when enabled regardless of the LOD being requested. Since the Nanite enablement parameter is set on all LODs in USkeletalMesh::BuildLODModel and LODs ...

Editor crash when using PCG self pruning and complex collision

UE - World Creation - Procedural Tools - PCG Workflow - May 14, 2025

While testing out pruning points based on collision, it was observed by the licensee that using complex collision seems to crash the editor. The editor crashes with the following error: ``` Asserti ...

[Interchange] Crash on asset re-import

UE - Editor - Content Pipeline - Import and Export - Feb 7, 2025

We've started seeing a crash in editor when re-importing one of our assets. <pre class="ql-syntax">Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 783] Array index out of ...

If pasting a section causes an overlap, don't allow it if the track doesn't allow overlapping sections

UE - Anim - Sequencer - Nov 4, 2024

Binding lifetime sections aren't meant to overlap, but duplicating one, or pasting one can cause them to overlap, triggering an ensure. Duplication and copying and pasting are typical actions, so th ...

LevelSequence Editor consumes input, even if the user last focused the Level Viewport

UE - Anim - Sequencer - Nov 27, 2024

LevelSequenceEditor has input priority over the Level viewport and other editor modules even though the Level viewport has been the last one selected. An example would be a cut operation. If you ha ...

Auto Reimport crash with some file paths

UE - Editor - Content Pipeline - Import and Export - Dec 14, 2016

Auto Reimport source paths can cause a crash with the editor. I couldn't narrow down in my limited testing what would cause the crash vs what would not with these file paths. The one in my attached ...

[Soundfield Submix][Crash] - Unreal Ambisonics Crashes on Packaged Game and in Standalone

UE - Audio - Submixes - Jan 11, 2021

Issue was reported by a user on the Unreal Engine forms. I tried to package the game with the other encoding options and this appears specific to using the Unreal Ambisonics option.  I have only co ...

NiagaraSystem with EniagaraGpuComputeTickStage::PostInitViews rarely crashes due to multi-thread race conflicts

UE - Niagara - Mar 1, 2025

NiagaraSystem with EEiagaraGpuComputeTickStage::PostInitViews should not have bSupportsParallelGDME because of possible multi-threaded contention, but FNiagaraSystemInstanceController::GetGpuCompute ...

Crash can occur when loading a sub level that contains an actor with a child actor component

UE - Gameplay - Dec 1, 2017

A licensee is reporting a crash where loading a sublevel that contains an actor with a child actor component can cause a crash. After speaking to Marc Audy, this seems to be related to the initializ ...

FAnimationRuntime::BlendPosesPerBoneFilter() causes an assertive crash when Skeletal Mesh LOD is changed

UE - Anim - Runtime - Nov 1, 2023

The crash occurs from "check(BoneBlendWeights.Num() == NumBones);" This crash occurs when the following conditions are met;The skeletal mesh LOD is changed.The number of bones is difference between ...