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 ...

Spawned actors with meshes become invisible in editor after changing level

UE - Graphics Features - Sep 7, 2018

When moving actors spawned from within the editor to a new sublevel, their meshes stop rendering. However, if you open a new level then re-open the old level the meshes become visible again. You wil ...

Inconsistent Red X icons when using World Composition

UE - World Creation - Worldbuilding Tools - World Composition - Sep 20, 2018

This issue takes a few attempts to repro. Sometimes when saving the icons will remain normal, but other times a red X will be displayed instead. Opening up the Level that is displaying the X and re= ...

CharacterMovementComponent causes the Character to slide when jumping on moving objects

UE - Gameplay - Player Movement - Sep 21, 2018

When the CharacterMovementComponent makes the transition from falling to walking, it retains the forward velocity it had while falling. When the character lands on the moving object, its new velocit ...

When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable

UE - Networking - Sep 25, 2018

When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable. It implies extremely high lag on each lost RPC and all following ones. User lose ...

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 [ ...