Updating Material does not update platform stats in derived Instance

UE - Rendering Architecture - Materials - Nov 26, 2024

It would seem that updating a material does not update the associated platform stats in a material instance editor, only the parameters. Can workaround by manually invoking shader compile in the ma ...

Enabling ZenLoader causes editor crash when undoing Level Instance deletion

UE - CoreTech - Sep 5, 2024

Crash reported through UDN. With ZenLoader enabled, deleting a level instance and triggering Undo causes a crash in  ULandscapeComponent::PostEditUndo() The user has provided an example project th ...

Physics Constraint no longer constrains components that are set to Query Only

UE - Gameplay - May 5, 2016

Physics Constraint no longer constrains conponents that are set to Query Only Regression from 4.11.2 User Description: Testing a 4.12 copy of my 4.11 project and when I tested in editor, all my ...

GPU Particle Collision causes shaking when set to bounce with low resilience.

UE - Niagara - Jul 27, 2016

A particle emitter with GPU sprites on certain settings will shake violently as they collide with the ground. This requires there to be a strong Const Acceleration module and Collision with low resi ...

SpeedTree Material No Longer Compiles With Texture Coordinate Node In BaseColor

UE - Graphics Features - Jan 25, 2017

If you open a material with the speedtree node plugged into WPO and then use a texture coordinate(index of 2) in base color the material will no longer compile properly. The full error is "Error [ ...

Iris - large fast arrays serialize multiple elements when only one is dirtied

UE - Networking - Iris - Apr 8, 2025

This seems to be a result of how the changemask is handled for fast arrays. Because the changemask is a fixed set of bits (defined by IrisFastArrayChangeMaskBits), a single bit can represent multipl ...

Mouse Events cannot be treated as Touch on Android Apps on Chromebook

UE - Platform - Mobile - Mar 18, 2019

A licensee reported an issue where mouse events are not able to be used as touch events on Android apps. This was specifically reported on and tested on Chromebooks. After working with Chris Babcock ...

Macbook Pro touchpad two finger click and drag does not rotate the viewport camera

Docs - Mar 14, 2018

Using 2 Finger Click + Drag to rotate the Viewport camera does not provide the behavior that is described in the documentation. Instead of rotating the camera in place as the documentation describe ...

Enabling Preview Rendering Level Mobile GLES3.1 on Map With Vector Fields Results in Editor Crash

UE - Platform - Mobile - May 21, 2018

Reproduced Crash on 4.18.3, 4.19.2, and Main CL 4081612. Licensee states: Based on a quick inspection of the code, it seems FVectorFieldVisualizationVertexFactory::ShouldCache() returns false (req ...

Project Crashes on UAIPerceptionComponent::RegisterStimulus()

UE - AI - Apr 26, 2016

Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 785] Array index out of bounds: 2 from an array of size 2 Source Context: 363 return OwnerController->GetPawn(); ...