Changing the name of a variable that references a Blackboard Key inside a Task removes the Key reference inside the Task's node in the Behavior Tree

UE - Gameplay - Blueprint - Oct 5, 2015

Changing the name of a variable that references a Blackboard Key inside a Task removes the Key reference inside the Task's node in the Behavior Tree. Clicking on the Behavior Tree's Task node that r ...

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 ...

Lightmaps on Mobile Devices Appear Dirtied and Pixelated

UE - Platform - Mobile - Jun 19, 2015

Baked lighting on mobile has dirtied or pixelated lightmaps. When testing this issue I attempted to change various settings within the 'Lightmass' section and the changes made did not have much effe ...

The "Random Integer in Range from Stream" returns the same value if the seed is power of 2 of anything above 22.

UE - Foundation - Core - Aug 7, 2019

When using the "Random Integer in Range from Stream" where the seed is a power of 2 after a certain point (2^22) the random integer that is returned is the always the same. If the seed is 2^23 + 1 i ...

When very far out from the map origin, large static mesh is not streaming in until player is close in world partition even though it's within loading range.

UE - World Creation - Worldbuilding Tools - World Partition - May 7, 2025

Context World Partition has a distance-based level streaming system that provides a complete solution for large world management. Problem The problem is that when the player and large static mesh a ...

Child actor passes a string to it's parent's overloaded constructor the incorrect string is received

UE - Gameplay - Sep 24, 2019

When a child actor passes a string to it's parent's overloaded constructor using an overridden function that returns a string it won't receive the correct string. I have verified that the correct fu ...

Vulkan leaks memory when opening and closing windows

UE - Rendering Architecture - RHI - Nov 22, 2019

As described here: https://udn.unrealengine.com/questions/532725/index.html (1) Start Prebuilt Vanilla 4.23.1. with Vulkan enabled (2) Create a new project (3) Drag and drop the Sphere from “modes ...

Instigator is no longer automatically set when spawning actors from blueprint

UE - Gameplay - Blueprint - Aug 20, 2024

Actors that are spawned from blueprints will no longer have their instigator automatically set to the instigator that spawned them. This is a regression in 5.5, because in 5.4 and earlier a null Ins ...

Does Container Match Tag Query Node doesn't find existing Gameplay Tags in Packaged Project with Nativized Blueprints

UE - Gameplay - Aug 26, 2019

When using the "Does Container Match Tag Query" node doesn't return true when a gameplay container member has the searched for gameplay tag in a blueprint that has been nativized. Packaging in Excl ...

Plane Constraint Normal is not Properly Reset

UE - Simulation - Physics - Jan 26, 2016

In the Character Movement Component, setting the Plane Constraint Normal to a value other than default, and then attempting to change the value back to the default does not revert to the default val ...