Unexpected behavior resulting from overlapping or touching physics actors when Simulate Physics is enabled through input

UE - Simulation - Physics - Sep 21, 2015

Weird behavior occurs when toggling Simulate Physics on physics actors by input instead of on BeginPlay. Multiple odd behaviors are present such as touching physics actors ignoring collision. Test ...

Application crashes when blueprint contains a copied timeline

UE - Gameplay - Blueprint - Oct 15, 2015

Copied timeline nodes triggers an Android crash and a black screen on the iOS devices. ...

Launch On from Windows to Linux fails with missing GLSL_430 shaders

UE - Platform - Linux - Nov 16, 2016

GLSL_430 shaders are not cooked when deploying a project from Windows to Linux using Launch On. LogPlayLevel: PLINK: [2016.11.16-18.36.22:414][ 0]LogMaterial:Error: The global shader cache fi ...

SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly

UE - Gameplay - Jun 4, 2024

The description of SpringArmComponent's "Use Camera Lag Substepping" option says "sub-step camera damping so that it handles fluctuating frame rates well". However, as noted and explained by a licen ...

Reflection Captures permanently unload with world streaming

UE - Rendering - Graphics Features - Jul 19, 2024

When a reflection capture is unloaded due to streaming, it cannot be reloaded when the player returns to that area in the world because FReflectionCaptureData::OnDataUploadedToGPUFinal deletes the C ...

MemReport does not seem to respect mesh streaming

UE - Rendering - Architecture - Aug 6, 2024

The function "FStaticMeshLODResources::GetResourceSizeEx(...)" does not take into account that the buffers might be emptied, due to Mesh Streaming. This causes "obj list" to report sizes larger than ...

UGeometryCollectionComponent::EventDispatcher gets registered for events twice what can result in duplicate collision events being fired

UE - Simulation - Visual - Sep 18, 2024

UGeometryCollectionComponent::EventDispatcher gets registered for events twice, once in UGeometryCollectionComponent::RegisterForEvents() and again in UChaosGameplayEventDispatcher::OnRegister(). Th ...

'Malformed sequence hierarchy' ensure hit after modifying sub-sequence tracks

UE - Anim - Sequencer - Sep 5, 2025

It's possible for there to be multiple instances of the same sequence in the evaluation states cache if the same sequence is used in multiple sub-sections. Caches are never removed from the evaluat ...

Local class variables do not correctly populate

UE - Gameplay - Blueprint - Dec 2, 2015

Local class type variables do not correctly populate with default value information. Variables of a class type populate with default value information normally. ...

Inside a BP Interface, changing a Function output to an input will cause a compile error in the reference bp

UE - Gameplay - Blueprint - Apr 6, 2015

Inside a BP Interface, changing a Function output to an input will cause a compile error in the reference bp. [Error] "Graph named 'NewFunction_0' already exists in 'bpActor'. Another one cannot be ...