Rare assertion comes up when cooking if sequencer camera track has only additive transform track

UE - Anim - Sequencer - Mar 2, 2020

If a camera track has only additive transform track, some functions return uninitialized F3DTransformTrackToken made by default constructor. It causes a rare assertion. Please take a look at F3DTra ...

Crash when splitting a UDS pin on a collapsed graph

UE - Gameplay - Blueprint - Jan 27, 2017

I came across this bug while attempting to verify UE-41073. That bug is verified, but I accidentally added the struct into the collapsed node without going into the collapsed graph and split the col ...

Instanced static mesh component PerInstanceSMData array defaults do not propagate from the owning Actor CDO to instances on edit.

UE - Gameplay - Blueprint - Nov 19, 2016

This occurs because the 'LightmapUVBias' and 'ShadowmapUVBias' struct fields (deprecated) are initialized in UInstancedStaticMeshComponent::SetupNewInstanceData() to nonzero vectors, but as these pr ...

FSkeletalMeshComponentInstanceData subclasses FSceneComponentInstanceData instead of FPrimitiveComponentInstanceData

UE - Anim - Rigging - Mar 19, 2025

FSkeletalMeshComponentInstanceData subclasses FSceneComponentInstanceData instead of FPrimitiveComponentInstanceData. When calling ApplyToComponent() the SceneComponentInstanceData version will be c ...

FInstancedStruct does not serialise to JSON when used in a DataTable

UE - Editor - Workflow Systems - Aug 4, 2025

The JSON export functionality for DataTable relies on a FieldIterator to gather properties. This iterator is unable to gather the properties from the InstancedStruct. CSV export functionality works ...

Crash when using both tessellation and virtual texture on a landscape material

UE - LD & Modeling - Terrain - Landscape - Feb 11, 2020

When a landscape is set up to use runtime virtual texturing. If it uses a material that writes to a runtime virtual texture and has tessellation enabled. Then we see a crash and the log reports: ...

[CrashReport] UE4Editor_DestructibleMeshEditor!UDestructibleChunkParamsProxy::PostEditChangeProperty() [destructiblechunkparamsproxy.cpp:18]

UE - Simulation - Physics - Destruction - Sep 14, 2017

This is a somewhat common crash occurring for users in 4.17 User Descriptionsdeleted something Source Context 7 UDestructibleChunkParamsProxy::UDestructibleChunkParamsProxy(const FObjectI ...

Recent Projects Missing Moved Projects After Browsing

UE - Editor - Workflow Systems - Nov 15, 2022

When an existing project is opened from a location where it hasn't been created on that machine, the Editor is unable to parse the project's location properly and fails to show it in the Project Bro ...

Cannot create Editor Toolbar Button with the name "Button"

Tools - Apr 19, 2017

The plugin fails to be created with the name "Button". The name button or BUTTON works as a plugin name. If there are some names that plugins cannot be called, then an error/warning message in the o ...

[UDN - 16673100] Calling FComponentVisualizer::NotifyPropertyModified() on a FInstancedStruct property loses all data inside because the PreviewActor spawns with default properties in the FInstancedStruct

UE - Editor - Workflow Systems - Jan 15, 2025

We found a problem with the component visualizer system and the PreviewActor in the Blueprint editor. If your component is using a FInstancedStruct in anyway, either directly, in a TMap, or TArray, ...