Regression: FAnimInstanceProxy memory leak when BeginDestroy() called on UAnimInstance before USkeletalMeshComponent

UE - Anim - Runtime - Feb 10, 2025

In UE 5.5, the fix applied by CL 36529858 in ue5-main updated USkeletalMeshComponent::ClearAnimScriptInstance() to call AnimScriptInstance::UninitializeAnimation() on the animation instance. This, i ...

Instigator is no longer automatically set when spawning actors from blueprint

UE - Gameplay - Blueprint - Aug 20, 2024

Actors that are spawned from blueprints will no longer have their instigator automatically set to the instigator that spawned them. This is a regression in 5.5, because in 5.4 and earlier a null Ins ...

Enabling ZenLoader causes editor crash when undoing Level Instance deletion

UE - CoreTech - Sep 5, 2024

Crash reported through UDN. With ZenLoader enabled, deleting a level instance and triggering Undo causes a crash in  ULandscapeComponent::PostEditUndo() The user has provided an example project th ...

Unable to scroll in Structure property window

Tools - Nov 16, 2016

When enough variables are added to a structure to cause the list to be too long for the window, a scroll bar should appear and you should be able to scroll through them. This does not occur. Regres ...

World Memory Leaks crash with a hidden sublevel to a redirector

Tools - Dec 8, 2020

From UDN: The reason it crashes is because Child doesn't get garbage collected, which is because it still has the RF_Standalone flag. UEditorEngine::EditorDestroyWorld clears RF_Standalone flag ...

Using the BuildGraph to create an installed binary build of the Engine will fail if Simplygon is not installed.

UE - Foundation - Horde - BuildGraph - Oct 13, 2016

A user reported that attempting to create an installed binary build of the Engine using BuildGraph will fail. This seems to be because we include the UE Simplygon implementation, but do not disable ...

Mutable: Child parameters hidden when intermediate Object Group uses "All Options"

UE - Anim - Mutable - Mar 31, 2026

FCustomizableInstanceDetails::FillChildrenMap() unconditionally registers parent-child relationships via __ParentParamName metadata without verifying the parent exists in the active parameter list. ...

Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity

UE - Rendering - Graphics Features - Nov 27, 2025

Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...

Landscape component's LODBias settings is ineffective

UE - Graphics Tools - Terrain - Landscape - Jan 7, 2025

[Image Removed] Jira Bot attaches conversation thread from Slack [Image Removed]Ryan Bickell – 2025-01-07 10:54:10 UTC Hello and happy new year! I'm messing with the Landscape component LODBias sett ...

GameInstance and subsystem initialization order is incorrect for Play In Editor

UE - Gameplay - May 18, 2023

The order of world and game instance initialization is different between a true standalone game (cooked game or an editor build with -game) and a Play In Editor game. Specifically, in Play in Editor ...