Indirect lighting samples incorrect if duplicated levels placed in same persistent level

UE - Graphics Features - Aug 29, 2017

Indirect lighting samples were not made correctly when building lighting with umap duplicated via the content browser and registering both source and destination as sublevels in one map. ...

Memory leak when Lumen is disabled but r.MeshCardRepresentation=1

UE - Graphics Features - Lumen - Jul 29, 2024

When Lumen is disabled, but the cvar "r.MeshCardRepresentation" is set to 1, Lumen will continuously enqueue object removal from the Lumen Scene, without ever emptying the array of primitives to rem ...

In Packaged builds, Chaos Cache Manager can't animate Geometry Collections with Nanite Enabled if Cache Mode is set to Static Pose

UE - Simulation - Physics - Destruction - Feb 27, 2025

In Packaged builds, Chaos Cache Manager (CCM) can't animate Geometry Collections (GC) with Nanite Enabled if Cache Mode is set to Static Pose. The licensee tried to animate a CCM using Sequencer onl ...

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Regression - Nested scene component subobjects are no longer being registered when the owning scene component is added to an existing Actor instance as an instanced component.

UE - Gameplay - Components - Nov 16, 2016

This is a regression that was introduced with changes made to address issues with native vs. non-native component registration at Blueprint construction time ([Link Removed]). Prior to those change ...

SelectActorsUsingThisAsset doesn't select actors that are referenced by an array and using a Scene component as root

Tools - Sep 11, 2015

SelectActorsUsingThisAsset doesn't select actors that are referenced by an array and using a Scene component as root User Description: I have a BP with editable actor references array. Recently I ...

[CrashReport] UE4Editor_MovieSceneTracks!UMovieSceneCameraCutSection::GenerateTemplate() [moviescenecameracutsection.cpp:24]

UE - Anim - Sequencer - Oct 30, 2017

This is a somewhat common Sequencer crash that occurs in 4.17 and 4.18. User DescriptionsWas trying to copy and paste a camera movement but something screwed up, I tried to add an already built Cam ...

[CrashReport] Fatal error: Cast of nullptr to Object failed

UE - Gameplay - Oct 5, 2017

This is a common and longstanding crash that has affected many users since at least 4.11. Source context not available (error in user code?). User DescriptionsI was duplicating a Set function in c ...

Mobile Previewer: Safe Zone Invalid Until Window Resize

UE - Platform - Mobile - Jul 12, 2021

When the Mobile Previewer loads, the Safe Zone widget is not working properly at startup, and requires a window resize to update to the correct Safe Zone. ...

Using dynamic bindings in a code class will result in the bindings becoming a permanent part of any Blueprint created from that class if a hot reload is performed.

UE - Foundation - Core - Mar 26, 2015

If dynamic bindings are being used in a custom code class from which Blueprints are derived, any hot reload will make the bindings a permanent part of the Blueprint and they cannot be removed or cha ...