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 ...

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 ...

Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level

UE - Graphics Features - May 14, 2025

Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...

Ensure triggered with multiple AddInstance() calls for InstancedStaticMeshComponent

UE - Graphics Features - May 20, 2016

Adding multiple instances to instance static mesh component in a code class causes an ensure to trigger when an instance of the class is added to the level. ...

Cannot compile nativized Blueprints containing a delegate signature that includes a TMap (paired) type as a parameter.

UE - Gameplay - Blueprint - May 15, 2018

Paired types (e.g. TMap) in a delegate signature do not compile after nativizing a Blueprint class containing it due to the macro expansion and comma inside the template spec between key and value t ...

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. ...

[CrashReport] UEdGraphSchema_K2::PinHasSplittableStructType

UE - Gameplay - Blueprint - Sep 14, 2017

This crash is affecting a few users in 4.17. ...

IOS crash disabling idle timer when closing the app

UE - Platform - Mobile - Apr 29, 2020

Licensee report of crash during shutdown due to setting [UIApplication sharedApplication].idleTimerDisabledbeing from the Game thread. Grouped together with others items in [Link Removed] ...

A Blueprint containing an array Swap node will fail to be nativized.

UE - Gameplay - Blueprint - Jul 17, 2020

Blueprint assets that utilize an array "swap" node to swap elements cannot currently be converted to C++. Current workaround: Either avoid use of the "swap" node or exclude the Blueprint asset from ...