[Audio][Niagara] - Audio Spectrum only reacts to Channel 0, despite setting to another channel

UE - Audio - Submixes - Jun 6, 2023

While doing some extra testing of the Submix Analyser fixes, I noticed there is a setting to set the channel of the submix to give the analyser. It always works for channel 0, but changing it to any ...

Random Stream variables in the GameMode are reset every PIE

UE - Gameplay - Blueprint - Jul 6, 2015

Random Stream variables in the GameMode are reset every PIE. Workaround is to use Set Random Stream Seed before using the Stream value. Reproduced in 4.7.6, 4.8.1, and Main (//depot/UE4/Promotable ...

Displaying Revision control history for a file ending in an "undo" of a revision can cause a crash

UE - Editor - Workflow Systems - Jun 18, 2024

This crash is caused by how source control history is managed and shown. In this specific case the source control software is Perforce. As written in the repro steps, it can happen to any uasset tha ...

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 ...

iOS will not package or launch on Win 10 machine

UE - Platform - Mobile - Sep 23, 2015

Launching or packaging for iOS does not work on our Windows 10 machine however we are able to package and launch onto iOS devices from Windows 7 machines. Using the File > Package > iOS option with ...

Self-Shadowing changes when click on and off an actor

UE - Graphics Features - Jun 19, 2015

Given a Movable Light with a Movable Mesh with enabled Self Shadow Only, the mesh will not cast inset shadows (despite this option begin forced to true according to Tooltip) unless the mesh is selec ...

[CrashReport] UE4Editor_BlueprintGraph!BlueprintActionFilterImpl::IsEventUnimplementable() [blueprintactionfilter.cpp:588]

UE - Gameplay - Blueprint - Jun 1, 2016

This crash has been reported through the 4.12 Previews and is continuing to occur in the 4.12.0 release. Additional information about this crash is not available at this time, however it may be the ...

ModularGameplay and other runtime plugins have wrong LoadingPhase

UE - Gameplay - Jun 30, 2022

Plugins that provide blueprint-accessible libraries generally need to be set the PreDefault LoadingPhase so they can be properly loaded before game-specific data that loads early in the Default load ...

UV Flipping Mode Causes Stretching of Particles

UE - Niagara - Nov 17, 2017

If "UVFlipping Mode" under Rendering on the Required node of an emitter is set to anything other than "None," the particles can become stretched and distorted. As a workaround, I have discovered th ...

LIVE: A Local Variable cannot have its type changed if another local variable with the same name in a different function is in use

UE - Gameplay - Blueprint - Nov 6, 2014

Two local variables with the same name in two different functions still interact with each other in some way. This was reported in TTP 346132 and fixed in that case, but currently if a local variabl ...