Float Curve evaluation may yield completely wrong results due to floating-point precision issue

UE - Runtime - Animation - Oct 31, 2024

Note: This is possibly related to [Link Removed] To Do . For some inputs, function UE::Curves::WeightedEvalForTwoKeys() ins ...

Crash on play if a BP uses a ClearInstances node followed by an AddInstance node

UE - Graphics Features - Jul 21, 2017

Crash on play if a BP manipulates a InstancedStaticMeshComponent by using a ClearInstances node followed by an AddInstance node. This is a blocker for the licensee. This is a regression: Working ...

The light in the Blueprint Editor's Preview Scene does not respond to any lighting channel but 0.

UE - Framework - Blueprint Editor - Jun 28, 2024

In the Blueprint Editor, Primitive Components can be configured to respond to Lighting Channels 0, 1, and/or 2. However, if channel 0 is disabled (even with another one enabled), the Preview Actor's ...

Tabbing out of exclusive fullscreen leaves the window & backbuffer in an incorrect state

UE - Editor - UI Systems - Apr 24, 2020

With windows 10 there has come some new swap chains, which unfortunately messes some things with regards to fullscreen up. We've fixed a bunch in the renderer (which would downright cause crashes), ...

If "Update Position Eash Frame" of "Skel Vert/Surf Location" is enabled, the particle continues to rotate.

UE - Niagara - May 25, 2020

It seems to have occurred since UE4.23, and the cause was the following part of "ParticleModules_Location.cpp".//From UE4.23 if (bOrientMeshEmitters) { //We have the mesh oriented to the normal o ...

ZenGarden or project with MSAA enabled crashes on iPhone 6 and 6+

UE - Platform - Mobile - Jul 19, 2017

Zen Garden crashes on the iPhone 6+ before anything appears onscreen. Occurred on: iPhone 6+ on 10.3.2 Didn't occur on: iPhone 6S on 10.3.2 ...

Behavior Tree (BT) services added to root nodes call the initial tick twice

UE - AI - Nov 20, 2024

Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...

Subsurface Scattering Checkerboard with SceneColourFormat 3 (High Scalability) leads to a visual artefact when temporal upscaling is in use

UE - Graphics Features - Sep 30, 2024

Primarily visible at very low internal resolutions (25-33%), the SSS checkerboard with an RGB scene colour format (r.SceneColorFormat 3) causes a double-image artefact both internally and on the sil ...

[CrashReport] UE4Editor_LandscapeEditor!FLandscapeEditorCustomNodeBuilder_TargetLayers::HandleAcceptDrop()

UE - LD & Modeling - Terrain - Landscape - Jul 6, 2017

This is a common crash affecting users in 4.16.2. It is similar to [Link Removed], which was potentially fixed in 4.16.2. Users have not provided any additional information. Source Context 803 ...

Custom Primitive Data on BP instance not taking affect while in editor

UE - Rendering - Architecture - Apr 5, 2023

Original Repo is from 4.27, however, it still happens in 5.2. This is happening because the Instance Data system does not update the field UPrimitiveComponent::CustomPrimitiveDataInternal from the d ...