Add Submix Effect Blueprint Does Not Have Any Effect

UE - Audio - Dec 11, 2020

Adding a second effect to the Submix Effect Chain on a Submix works as expected, but when trying to add a Submix Effect via Blueprint, there is no effect.  This also applies to "Add Master Submix Ef ...

Get Mouse Position Blueprint node returns different values outside of viewport depending on whether it was called from Event Tick, or within an Actor function

UE - Gameplay - Nov 15, 2018

There seems to be a discrepancy between the output of Get Mouse Position node depending on whether the node is inside an Actor function or called from Event Tick. If the node is present inside a fun ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

Culling Distances Not Working For Static Mesh in Procedural Content Generation Tool and Foliage Tool

UE - World Creation - Procedural Tools - Mar 28, 2025

When creating Foliage or Procedurally Generated Content the culling settings of the Static Meshes do not apply correctly. As soon as either a minimum or maximum cull distance is set the Static Meshe ...

BuildPatchTool doesn't finish if enabled building Http Chunk on Mac

Portal - Jan 25, 2021

We may fix this issue by the following codes. FPakPlatformFile::FPakPlatformFile(): LowerLevel(NULL) ,bSigned(false) { // remove //FCoreDelegates::GetRegisterEncryptionKeyMulticas ...

ES2 Fallback Fails on Nougat Devices that do not support Vulkan

UE - Platform - Mobile - Aug 28, 2016

Discovered this while doing RC candidate testing for 4.13 Works fine in all other use cases: Nougat devices that support Vulkan Marshmallow devices that support Vulkan Marshmallow devices that don' ...

Create Session does not work in a packaged game from any project that has used C++

UE - Networking - Dec 28, 2015

After adding C++ to a content-only project, Create Session no longer works in a packaged game. The following warning appears in the log: LogScript:Warning: CreateSession - Invalid or uninitialized ...

VR Preview crashes when the number of players is greater than one

UE - Platform - XR - Aug 18, 2015

If the user has the number of players set to more than one, the VR preview will crash. ...

[CrashReport] USpeedTreeImportFactory::FactoryCreateBinary()

UE - Editor - Content Pipeline - Import and Export - Sep 19, 2017

This is a common and longstanding SpeedTree import crash that has occurred since at least 4.14 for over 100 users. This seems to be the same issue as a previous Jira from 4.10 which was closed wit ...

Deferred spawned actors can receive BeginPlay before they are finished spawning

UE - Framework - Performance - May 18, 2023

Actors that are deferred spawned on BeginPlay can be added to the world while AWorldSettings::NotifyBeginPlay is still iterating the world's actors and dispatching BeginPlay. AActor::DispatchBeginPl ...