In the level editor, when configuring a component that is part of an actor blueprint, adding entries to a TMap with C++ enum keys results in duplicate keys and an incorrect warning popup.

UE - Editor - Jan 22, 2026

Note: This started happening in UE 5.4 and persists up to latest. It is probably related to [Link Removed] Closed ([Link Re ...

StateTree: While editing State Parameters or exposed properties of a Condition/Task, an ensure() fires when editing inputs of a Property Function bound to an array element

UE - AI - StateTree - Mar 5, 2026

Consider an array property that can be edited in the StateTree editor. This can be a State Parameter or an exposed property of a Condition or Task, for example. Each element of the array can be boun ...

Chaos: geometry collection with One Way Interaction never breaks from its own collisions

UE - Runtime - Simulation - Aug 21, 2026

A geometry collection with One Way Interaction Level set to 0 never breaks from its own collisions. It falls, lands, and stays intact no matter what it hits. Set the level to -1 (feature off) and ch ...

Grabbing a Destructible Mesh Child blueprint with a Phsyics Handle crashes the editor

UE - Simulation - Physics - Jun 20, 2016

Grabbing a Destructible Mesh Child blueprint with a Phsyics Handle crashes the editor during PIE. NOTE: This issue occurs whether or not simulate physics is active on the destructible mesh compone ...

Full Scene Importer Blueprint will only set as Movable Components

UE - Editor - Content Pipeline - Import and Export - Jun 22, 2016

When importing a full scene using the Full Scene Importer and having it create a Blueprint actor that will set it's default mobility to static. Even unchecking the Import as Dynamic option will not ...

UE 4.6.1 Memory Game Causes Mac OSX to Crash

Tools - Jan 19, 2015

On a Mac running OSX 10.10.1, the launcher crashes when the user selects the "Memory Game" located in the "Learn" section under "Example Game Projects." ...

UStereoLayerComponent cleaning up too late

UE - Platform - XR - Jan 3, 2017

Naming CustomEvent string Input "DisplayName" breaks Blueprint Node

UE - Gameplay - Blueprint Editor - Jan 4, 2018

Naming a custom event string input DisplayName will cause the BP Node spawner to use blank or user-entered data for node listing+creation. Additional Notes: This also occurs when renaming the Text ...

UMG screen size setting needs update for new mobile devices

Tools - Oct 29, 2018

We're missing settings for iPhone XS iPhone XS Max iPhone XR Google Pixel 3 Google Pixel 3 XL Samsung Galaxy Note 9 We also don't have settings for iPad 5th Gen or iPad 6th Gen, however these would ...

Datasmith Metadata is lost when actor is converted as BP

UE - Editor - Content Pipeline - Datasmith - Importer - Dec 7, 2018

This behavior does not occur on actor tags and component tags so it is something we haven't considered when adding the metadata feature. ...