Crash occur when loading AInstancedPlacementPartitionActor

UE - Editor - May 17, 2022

Crashes when loading an actor that inherits from AInstancedPlacementPartitionActor. There is a serialization size mismatch. ...

Preview Meshes in Material Instances lose their association to material on close.

UE - Rendering - Architecture - Materials - Aug 13, 2015

When you assign a Preview Mesh to a Material Instance, save and close the instance, on reopening instance, the Preview Mesh will not retain connection to the Instance and will revert back to its ass ...

UMG Visibility binding resets to default after closing and reopening project first time

UE - Editor - UI Systems - Aug 31, 2017

UMG Visibility binding resets to default after closing and reopening project first time. "Get Visibility" on Button click boolean toggle for widget blue print "False" return node value gets automa ...

Video files do not play in scene after LaunchOn to iOS from Windows

UE - Platform - Mobile - Sep 30, 2016

While attempting LaunchOn to an iOS device, the video and audio does not play. Attempts were made using the following video formats:mp4movavi Attempts were made using the following devices:iPhone 5 ...

Eyedropper in the Color Picker window does not grab any color values on Mac/Linux

UE - Graphics Features - Jan 5, 2018

Trying to use the eyedropper in the color picker window on Mac fails to grab any color values. The colors will only update when hovering or clicking within the viewport but the colors shown aren't c ...

ScreenAlignedUVs Node with X 100% and Y 100% Breaks Infinite Hallway Effect of Portals

UE - Graphics Features - Nov 27, 2018

A SceneCaptureComponent2D is able to correctly capture the infinite hallway effect for portals. The " X 100% Y 100%" of ScreenAlignedUVs node is necessary to create the material that produces the co ...

Debug information is sometimes missing when compiling with cl-clang

UE - Foundation - Cpp Tools - UnrealBuildTool - Aug 24, 2023

Via UDN: As has been discussed previously here and in CL 20055361, debug information is sometimes missing when compiling with Clang. We've pinpointed this to debug information not being emitted fo ...

Ensure triggered in FBoundsCacheElement::GetValue when adding ISM instances in Construction Script

UE - AI - Oct 8, 2025

An ensure is triggered in FBoundsCacheElement::GetValue when adding instances to an InstancedStaticMeshComponent inside a Blueprint’s Construction Script. This occurs when the ISM component is navig ...

FIntVector has some code that refers to it being two dimensonal

UE - Gameplay - Mar 10, 2016

There is code in the FIntVector class (IntVector.h) that seems to be copied from the FIntRect class which is a problem since FIntRect is two dimensonal while FIntVector is three dimensional. The one ...

SpeedTree Material No Longer Compiles With Texture Coordinate Node In BaseColor

UE - Graphics Features - Jan 25, 2017

If you open a material with the speedtree node plugged into WPO and then use a texture coordinate(index of 2) in base color the material will no longer compile properly. The full error is "Error [ ...