Generated definition of BlueprintNativeEvent UFUNCTION in an interface does not include const keyword for return type

UE - Foundation - Core - Aug 15, 2018

UHT does not correctly create generated code for BlueprintNativeEvent UFUNCTIONs in an interface that return const values. In the corresponding .gen.cpp file, the generated code does not include the ...

Actor being moved via sequencer has inherited velocity that ignores play rate scale

UE - Anim - Sequencer - Nov 8, 2019

When an actor that can be stood on and jumped off of is moved in a sequencer it's inherited velocity doesn't scale with the Sequence play rate. If you jump in the opposite direction the cube is goin ...

GPU System will kill existing particles if activate is called after it has be deactivated

UE - Niagara - Oct 22, 2020

Deactivating and then reactivating the same GPU system will cause existing particles to die. ...

Runtime Virtual Texture primitives set to never render to main pass still cause occlusion queries

UE - Graphics Features - Mar 23, 2021

RVT only primitives are being pushed through the occlusion culling. It would be more efficient to not do that. ...

Pasting a component binding onto a Spawnable will not set up parenting correctly

UE - Anim - Sequencer - Aug 6, 2021

It appears that for spawnable bindings, when adding a child binding through a copy/paste it is not added to the child bindings array on the spawnable, so when GetChildPossessables is called, there a ...

Ensure condition failed: bPlayingBackwards ? (CurrentPosition <= PreviousPosition) : (CurrentPosition >= PreviousPosition)

UE - Anim - Sequencer - May 10, 2022

The problem is caused by the animation sequence playback position being set out of range from Sequencer. The call stack is :  UE4Editor-AnimGraphRuntime.dll!FAnimSequencerInstanceProxy::UpdateAnim ...

Mesh Paint mode's Texture Paint has obvious artifact with UV seams

UE - Rendering Architecture - Oct 8, 2024

Mesh Painting Texture Paint tool can miss some pixels along UV seams, even with "Enable Seam Painting" set to True. This appears to be because of the difference between rasterization and sampling. ...

Network Prediction crash when smoothing service instance data is reallocated out from under FNetworkPredictionStateView

UE - Gameplay - Network Prediction - Apr 4, 2025

Received a report from a licensee using Network Prediction Plugin and Mover.  There is a strong likelihood of a crash occurring when using NPP's smoothing option and spawning new NPP-simulating ins ...

Rendering sequence with livelink data has issues with smooth engine offset

UE - Virtual Production - IO - LiveLink - Apr 26, 2023

[Link Removed] for reference Playing back a sequence shouldn't have buffered samples. We should have a single one, which was built from the sequence. We need to make sure when played back that it ...

Alpha Textures reimported via overwriting disappear from level

UE - Graphics Features - Nov 10, 2014

When you reimport a texture that has an alpha by Importing and then overwriting the previous texture, all versions of that texture in any material or in the level complete disappear until you compil ...