Blueprints copied or moved to another level do not retain variable references to other Actors that are also copied or moved

UE - Gameplay - Blueprint - Apr 17, 2015

Blueprints copied or moved to another level do not retain variable references to other Actors that are also copied or moved. Reproduced in 4.7.5 binary and Main (//depot/UE4/Promotable-CL-2507843) ...

Complex Collision as Simple causes odd Overlap behavior

UE - Simulation - Physics - Jan 25, 2016

When triggering overlap events with a Static Mesh using Complex Collision as Simple, the overlap Begin and End events will be triggered rapidly in sequence. Changing to Default collision will fix t ...

Mobile Preview dynamic shadows not showing on Mac

UE - Platform - Apple - Dec 19, 2014

When Using mobile preview in the 4.7 preview build, or in the changelist provided, Dyanmic lighting is not showing shadows when changed to movable. Following the steps below, you will see no shado ...

UObjects returned from "Get Item Children" in a TreeView widget causes an engine crash, due to invalid pointers

UE - CoreTech - UObject - Jun 9, 2020

UObjects returned from "Get Item Children" in a TreeView widget causes an engine crash, due to invalid pointers. User has proposed the following fix: The best fix is probably such: When Slate list ...

Crash when adding sphere reflection capture to a scene

UE - Graphics Features - Jan 30, 2017

An occasional crash occurs when adding a sphere reflection capture to the scene from the place mode panel. This issue has a low repro, but has been seen a couple times. Repro rate seems to be around ...

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 ...

D3D11 error when opening a level after version change

UE - Graphics Features - Sep 23, 2015

After converting from 4.7.6 to 4.9.1 specific maps won't open and will crash the editor with a D3D11 error. This has been reported by multiple users but has not been reproduced internally. CrashRe ...

Static mesh's material slot's cast shadow does not require a build of StaticLight

UE - Graphics Features - Dec 7, 2017

If static mesh's material slot's cast shadow is changed, UE4 does not show "LIGHTING NEEDS TO BE REBUILT". I solved it with the following fixes. StaticMeshEditorTools.cpp void FMeshSectionSettin ...

Building Lighting will Generate Additional Lightmaps after Rotating Lightsource

UE - Graphics Features - Jul 7, 2015

Lightmap sizes seem inconsistent after rotating a light source and rebuilding the lighting. This causes concern about file sizes when packaging the project that is using baked static lighting. The ...

Clicking a button in UMG stops all tilt information

UE - Editor - UI Systems - Nov 14, 2014

Tilt information is no longer taken after clicking on a button in UMG. The tilt information goes to all zeros. That is until the user clicks else where at which point the device will then start regi ...