Niagara Simulation Stage + DynamicMaterialParameters crash

UE - Niagara - Feb 6, 2021

deleting the code "&& SimulationStages[i]->bEnabled" in UNiagaraEmitter::GetScripts will bypass the problem [Image Removed] ...

Left Clicking a menu that contains an option with a submenu will cause the submenu to close while hovering its options

UE - AI Workflows - UI Systems - Mar 25, 2022

If a menu has an entry that is a submenu, and that submenu has entries in it that are also submenus, then the entire menu will close when left clicking the submenu button instead of hovering it. So ...

FAnimUpdateRateParameters::GetInterpolationAlpha appears to be returning an invalid value for TrailMode

UE - Runtime - Animation - Aug 5, 2023

It appears that  FAnimUpdateRateParameters::GetInterpolationAlpha is not returning a sensible value when running in TrailMode.  Currently the only variable in the calculation is EvaluationRate which ...

Missing display units initialization from project settings

UE - Editor - Jun 11, 2024

From customer: Hi there, I stumbled upon a bug where the display units as set in the Project Settings under the Editor Appearance category for properties were not getting displayed properly and was ...

Material Emissive Color not working with SkyAtmosphereIlluminance Material Expression

UE - Rendering - Features - Jan 9, 2025

A licensee has reported that they are unable to use an emissive material utilizing the SkyAtmosphereLightIlluminance material expression together with Nanite and Lumen. The linked UDN has some more ...

Control Rig Creation Crash Triggered by “skel” Prefix in Skeletal Mesh Name

UE - ACT Character - Control Rig - Nov 27, 2025

When generating a Control Rig from a Skeletal Mesh that contains “skel” in its name—or uses it as a prefix (i.e. skel_test)—Unreal Engine crashes. The crash occurs both when using the native Creat ...

iOS builds fail on Windows.

UE - Platform - Mobile - Systems - May 15, 2026

Loading Windows installed iOs mobile provisioning profiles fails at start of iOS build from windows machine. This due to a recent change that attempts to load PKCS12 from mobileprovision files. Thes ...

Blueprint Editor: BP functions display dropdown instead of checkboxes for uint8 enum parameters

UE - Gameplay - Blueprint Editor - Aug 8, 2017

I traced through the callstack and it looks like the problem is as follows:in order for the BP function to compile, its enum parameter must be uint8, because that is the only type supported by BP fu ...

Game sounds only play during first PIE editor session for Linux project

UE - Platform - Linux - May 11, 2015

Games sounds will play as appropriate during first PIE session but subsequent PIE sessions have no sound until editor is closed / reopened. ...

Get Ping in ms returns 9999 in a packaged game when tested on systems not on the same network

UE - Networking - Feb 25, 2016

Get Ping in ms returns 9999 in a packaged game when tested on systems not on the same network. This does not prevent Client connection to the Server. Note: my understanding is this would be caused ...