Unreal Engine Issues
Unreal Engine Issues
Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile
UE - Framework - Blueprint - Apr 17, 2025Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...
Level Instance Property Override: Actor::Tags overridden pre-CS but clobbered by RerunConstructionScripts with no post-CS re-apply
UE - World Creation - Worldbuilding Tools - May 4, 2026Summary When using the Level Instance Property Override system, overrides applied to `AActor::Tags` are silently lost for Blueprint actors whose Construction Script assigns or appends to `Tags`. The ...
Compile error during build stage when packaging for tvOS
UE - Platform - Mobile - Dec 9, 2016Compile error packaging for tvOS: Does not affect iOSUATHelper: Packaging (tvOS): UnrealBuildTool: D:\Build\joseph.wysosky_Main\Engine\Source\Runtime\Core\Private\iOS\IOSAppDelegate.cpp(388,12): ...
[CrashReport] Mac crash - UE4Editor-Slate.dylib!SMenuAnchor::SetIsOpen()
UE - Platform - Apple - Sep 14, 2017This is a common and longstanding Mac crash that has occurred since at least 4.11 and affected more than 40 users. Users have not provided any descriptions of their actions when the crash occurred ...
FSkeletalMeshMerge::CalculateLodCount calculates minimum LODs improperly
UE - Gameplay - Aug 23, 2016CalculateLodCount tries to bound the output LOD count as at least one (count >= 1), but actually bounds it as no more than 1 (count <= 1). Just need to change a FMath::Min to FMath::Max. ...
[CrashReport] Crash on FMaterialEditor::OnCanPromoteToParameter()
UE - Rendering - Architecture - Materials - Jun 22, 2017This is a common crash in the 4.16 release (affecting Windows and Mac). A log file is attached. Users have not provided descriptions so additional information is not currently available. Windows C ...
A C++ project with the name, "GearVR", will not build
UE - Foundation - Core - Jul 28, 2015A C++ project with the name, "GearVR", will not build. This does not occur with content-only projects named GearVR. In 4.7.6 and 4.8.2, it fails during Compiling and an error message appears: Runni ...
GoogleVR apps prevent adjusting the volume for the phone while running
UE - Platform - XR - Oct 3, 20164.13.1 has caused an issue where the volume can no longer be adjusted for a GoogleVR application. This is a regression of functionality in 4.13.0. Tested with build: Working: 4.13.0 Binary CL-310 ...
StateTree: While editing State Parameters or exposed properties of a Condition/Task, an ensure() fires when editing inputs of a Property Function bound to an array element
UE - AI - StateTree - Mar 5, 2026Consider an array property that can be edited in the StateTree editor. This can be a State Parameter or an exposed property of a Condition or Task, for example. Each element of the array can be boun ...
Lens Flares are appearing in Other Player's Windows
UE - Graphics Features - Jul 28, 2015On a Windows 8.1 Platform with an Nvidia 960 card, Lens Flares when playing with 2 Player's (without a dedicated server) are appearing in the wrong window. So, Player 1 is looking at sun, Player 2 ...