Lightmaps on Mobile Devices Appear Dirty and Blurry

UE - Platform - Mobile - Nov 28, 2017

When deploying project to a mobile device, the quality of the baked lighting and shadows becomes very poor compared to "Mobile Preview." Lightmaps appear dirty and blurry, with splotches (As shown i ...

Undo after disconnecting a target pin will cause a series of internal compile errors

UE - Gameplay - Blueprint - Mar 15, 2016

Undo after disconnecting a target pin will cause a series of internal compile errors User Description: I've run into what I think is a bug when attempting to compile a blueprint after mistakenly b ...

Crash While Compiling Blueprint in FBlueprintEditorUtils::RefreshExternalBlueprintDependencyNodes()

UE - Gameplay - Blueprint - Jun 7, 2016

Having an actor blueprint (A) that contains an array variable of references to another actor (B) that is connected to a Length node and a Vector array that is connected to a ForEachLoop causes bluep ...

Behavior of configuration file hierarchy is different from document

UE - Foundation - Core - Nov 6, 2015

Licensee reported behavior of configuration file hierarchy is different form document here (https://docs.unrealengine.com/latest/INT/Programming/Basics/ConfigurationFiles/index.html) Doc: 1. Engine ...

Insufficient precision of Decode71 function

UE - Rendering Architecture - Shaders - Jun 5, 2025

Encode71 and Decode71 in DeferredShadingCommon.ush are functions that convert 8-bit values ​​to 7-bit values ​​and mask values, and licensees have reported that the accuracy is insufficient when usi ...

WP HLOD Crash on Small Cell Sizes

UE - World Creation - Worldbuilding Tools - HLOD - Jan 8, 2024

Saving Behavior Tree with Blueprint task inheriting from native class invalidates Blackboard key when BP contains a function

UE - AI - Jul 8, 2025

A regression introduced in UE 5.6 causes Blackboard key selectors in Blueprint tasks to become invalid when the Blueprint inherits from a native subclass of UBTTask_MoveTo (or UBTTask_BlackboardBase ...

iOS/tvOS fails to build from source editor built with Xcode 9.3, macro expansion producing 'defined' has undefined behavior

UE - Platform - Mobile - Apr 2, 2018

Trying to launch on or package for TVOS or iOS from a source build of Mac or Windows will fail with errors:[2018.04.02-16.35.08:522][634]LogPlayLevel: In file included from /Volumes/Storage/GitHub ...

CapsuleComponent Shape sometimes reverts to previous value after entering a new value

UE - Foundation - Core - Nov 28, 2014

If you manually type in the value for Capsule Half Height, it will sometimes revert back to it's previous value upon hitting Enter. The CapsuleComponent's shape in the Blueprint's Viewport adjust to ...

[CrashReport] UE4Editor_CoreUObject!StaticAllocateObject() [uobjectglobals.cpp:2153]

UE - Anim - Sequencer - Jun 3, 2016

Really close to the repro steps for [Link Removed] Same repro steps produced the following Buggs along with this one: [Link Removed] [Link Removed] Error message: Fatal error: [Link Removed] [Lin ...