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 ...

PhysicsBall BP not updating location with Collision volumes

UE - Simulation - Physics - Feb 2, 2017

PhysicsBallBP is unable to teleport via a collision volume (with either SetActorLocation or Teleport node). Regression: Error is not present in 4.14.3 but is present in 4.15.P3 Console error descr ...

Subsequent packaging attempts fail when packaging with Chunks, Nativization, Full Rebuild and For Distribution enabled

UE - Foundation - Cpp Tools - Automation Tool - May 4, 2017

Subsequent packaging attempts when Generate Chunks, Blueprint Nativization, Full Rebuild, and For Distribution are enabled will fail. The error that appears states that the AutomationTool log file i ...

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 ...

Gameplay Ability System Attribute Modifiers with a duration (including infinite) do not respect tag requirements

UE - Gameplay - Gameplay Ability System - Feb 21, 2024

When using infinite or duration-based effects, required and ignored tags will have no effect on attribute modifiers. This appears to be caused by OnAttributeAggregatorDirty (GameplayEffect.cpp:2917) ...

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

UE - 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 ...

Physics objects will bounce unrealistically just before coming to rest

OLD - Anim - Jun 5, 2017

Physics objects will bounce unrealistically just before coming to rest. This is most noticeable with the large cube in the 1st Person template project. It also happens with the smaller cubes but not ...

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 ...

Event Dispatcher not being called in 4.6

UE - Gameplay - Blueprint - Dec 8, 2014

ED nodes in 4.6 but are not being executed in standalone or cooked games. Also, users receive compile errors when the project is saved and reopened that resolve when the blueprint is recompiled. ...

Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5

UE - Framework - LWC - Jan 15, 2024

FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...