Breaking a level instance can not remove the level instance from world

UE - World Creation - Worldbuilding Tools - Level Instances - Nov 5, 2024

Currently there is no stable way to break level instances ...

Physics Constraints do not have the same values if they are part of an 'Always Loaded' level

UE - Gameplay - Dec 3, 2014

Physics Constraints do not have the same values if they are part of an 'Always Loaded' level. They will work correctly in the Persistent level and a level that is Streamed in. This becomes problem ...

Set user focus for player 0 will cause other local players to lose input

UE - Gameplay - Input - Feb 28, 2019

When the player at index 0 sets its user focus it will cause other players to lose input. This does not occur when setting the user focus of players with an index higher than 0. ...

Android ETC2 Debug Builds Crash on Startup

UE - Platform - Mobile - Sep 9, 2020

Android apps build with the debug configuration on ETC2 will crash on launch. ...

Crash when using Ctrl+Z to undo a single digit change in the size of a widget

UE - Anim - Sequencer - Feb 21, 2017

When trying to undo a single digit change the editor will crash. For example, if a user highlights and replaces a single number in the size of a widget and then attempts to undo, the editor will cra ...

Lighting channels not working as expected when enabling Ray Tracing Shadow

UE - Graphics Features - Lumen - Oct 13, 2020

Non-Ray Tracing Shadows are only cast from lights on meshes assigned to the same Lighting Channel. When enabling Ray Tracing Shadows this is not the case. Lights will still cast Ray Tracing Shadows ...

Crash when calling SetState inside state machine OnUpdate

UE - Anim - Sep 5, 2025

The crash happens when SetState is called inside the function bound to OutputAnimationPose’s OnUpdate in the animation state. This way of using Set State node is the same as shown in the official do ...

Crash, Couldn t find Shader FHitProxyVS for Material Resource M_Glass

UE - Graphics Features - Aug 18, 2014

Changing the properties of M_Glass and M_Metal_Copper to two sided via the property matrix crashes the editor to desktop. (Note: M_Glass with ANY of the M_Metal Materials except M_Metal_Chrome will ...

Crash when using StaticDuplicateObject with mismathced Source and Destination class types

UE - Foundation - Jun 19, 2025

Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...

Editor crash when adding mesh renderer elements in Niagara

UE - Niagara - Jul 8, 2025

When adding multiple meshes to a Niagara Mesh Renderer Module, a check() will be triggered due to a mismatch in the number of Widgets and the number of Tooltip Widgets. ...