4.6 Delegate error in Blueprints

UE - Gameplay - Blueprint - Dec 12, 2014

When looking into the bd_hud_scoring and bd_rules_maze blueprints in the users project (Provided below), there are nodes that are throwing errors. If you press compile, the errors go away and the co ...

FBX export from UE4 with multiple materials the UV is corrupted

Tools - Apr 18, 2016

When exporting a Static Mesh from within UE4 that has multiple materials, some of the material IDs will be condensed into a single ID which will mess up how the material assignment for that part of ...

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 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 ...

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 ...

Landscape Paint Layers will not scroll to the end when using mouse wheel

UE - LD & Modeling - Terrain - Landscape - Sep 28, 2020

In a normal detail panel, each element has its own SDetailSingleItemRow and are mostly uniformly sized with some exceptions of having a few bigger rows (i.e. asset pickers). However, these layers ar ...

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 ...

New C++ Class (actor) fails to build

UE - Foundation - Cpp Tools - Mar 8, 2022

While trying to create a C++ actor to test if it can be created with a custom Copyright notice specified in Project Settings, the Live Coding window returns a "Build failed" and error of: "ERROR: U ...

Duplicate .so files in GoogleVR.

UE - Platform - XR - Jun 2, 2017

A licensee recently pointed out that there are now several GoogleVR lib files in 4.16 that are present in the Engine twice due to some of them being copied into a subdirectory. For example, , in 4.1 ...

Stencil that has been marked with ResponsiveAA is cleared by DistortionPass

UE - Graphics Features - Dec 14, 2021

From UDN: When an object with ResponsiveAA enabled is in the screen and then an object with Distortion enabled comes into the screen, ResponsiveAA does not work. ​ I guess this is because the Ste ...