Removing a parameter from a blueprint function in a library can cause actor classes calling it to lose their parent or instance data

UE - Gameplay - Blueprint - Oct 4, 2018

Compile errors caused by an actor calling a function with something hooked up to a removed parameter can cause that actor to lose it's place in the hierarchy. Typically, the actor will be fixed once ...

Crash occur when using AddSpawnableFromClass with BlueprintGeneratedClass specified

UE - Anim - Sequencer - Aug 13, 2019

BlueprintGeneratedClass is not based UBleupint. So the following code is failed. bool UActorFactoryBlueprint::PreSpawnActor( UObject* Asset, FTransform& InOutLocation) { UBlueprint* Blueprint = ...

App fails to open on Android: Assertion failed referencing LaunchAndroid.cpp:415

UE - Editor - Content Pipeline - Datasmith - Importer - Oct 11, 2018

AR App fails to open on Android: Assertion failed referencing LaunchAndroid.cpp:415 when Unreal Datasmith is installed.10-11 11:22:57.499: D/UE4(18917): LogAndroid: Error: Assertion failed: false [F ...

Niagara GPU particles will always have a lifetime of one second if they use a Collision Module

UE - Niagara - May 2, 2019

GPU Particles will always have a lifetime of one second when using a collision module. This is a result of an issue with how off screen timing is handled. GPU particles that are off screen should on ...

Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile

UE - Framework - Blueprint - Apr 17, 2025

Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...

Media Player not updating when IMG Media Source files are changed

Media Framework - Aug 20, 2020

Images in a sequence path for an Img Media Source are not updating without restarting the project. Changing the path itself appears to work as expected.  Tested in versions 4.22.3(CL 7053642), 4. ...

Certain materials are overly bright with Ray Traced Global Illumination denoiser

UE - Graphics Features - Lumen - Mar 14, 2019

Ray Traced Global Illumination is causing some materials to glow extremely bright Disabling r.raytracing.globalillumination.denoiser fixes the issue In 4.22 preview 5 binary (5365847) the result i ...

Cloth paint update issues

UE - Simulation - Physics - Jan 7, 2020

Activating and Deactivating Cloth Paint marks the skeletal mesh as dirty, even if no values were painted and there is no transaction in the Undo History. Painting Max Distance values from non-zero ...

Crash when destroying a geometry collection actor

UE - Simulation - Physics - Aug 7, 2020

When an actor with geometry collection is destroyed, the engine doesn't remove elements from array in the ChaosSolver So illegal references occurs. Removing element with following quick fix code ...

Full Screen Native Resolution not supported on new iPad Pro 11-inch and iPad Pro 12.9 inch (3rd generation)

UE - Platform - Mobile - Nov 16, 2018

A licensee has reported that Full Screen native resolution does not work properly on the iPad Pro 11-inch and on the iPad Pro 12.9-inch (3rd generation). Black borders are used around the screen ins ...