Pressing ESC while on a drag operation makes drag visual to be disappeared and OnDragCancelled not to be called.

UE - Editor - UI Systems - Dec 11, 2018

DragDropOperation is removed when pressing esc button. but this is skipping OnDragCancelled so it can disrupt user's UMG drag operation logic.  ...

When using Lighting Scenario, loading order will affect how it's applied to the instances

UE - World Creation - Worldbuilding Tools - Foliage - Mar 7, 2019

When using Lighting Scenario, loading order will affect how it's applied to the instances, resulting in corruption if content is loaded after the lighting scenario ...

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 ...

RenderDoc plugin crash exiting

UE - Rendering Architecture - RHI - May 23, 2019

Review/unify dithering and fading systems

UE - Graphics Features - Jan 25, 2016

High priority item: "Hi guys, I was looking to a GPU capture of our foliage and all draws were set with the KILL_ENABLE register enabled. This register force off Early Z rejection since the GPU ha ...

Rounding errors are present in FJsonValue::TryGetNumber(int64&) and FMath::RoundHalfFromZero()

UE - Foundation - Core - Mar 8, 2019

A licensee reported a bug in rounding of a call to FJsonValue::TryGetNumber(int64&) with large values.  In investigating this, it appears that equivalent problems also exist in FMath:: rounding func ...

Fbx re-import material issue on LOD 1 and more

UE - Editor - Content Pipeline - Import and Export - May 13, 2019

When the material order of embedded fbx LOD change differently in LOD 0 and LOD 1, the LOD 1 is wrongly assign when re-importing. ...

NumNonClothingSections logic is bad

UE - Editor - Content Pipeline - Datasmith - Jul 26, 2019

We use the NumNonClothing section number to iterate in the sections, this is an error if the cloth sections are not at the end of the sections array. See the following picture of a search on NumNonC ...

The socketbuilders do not properly join multicast groups on iOS

UE - Networking - Jul 26, 2019

On iOS, using the code in the UDP socketbuilders causes the sessions tool to not join with iOS devices. Giving the error EADDRNOTAVAIL. If the user falls back to the other code function that uses th ...

Deferred Decals Fade In With No Fade Duration Set

UE - Graphics Features - Aug 9, 2019

Decals fading in with Fade Duration set to zero. Found in 4.21 CL# 4753647, 4.22 CL# 7053642, 4.23 Preview 5 CL# 7838574 ...