FMaterialResource::IsDualBlendingEnabled bug

UE - Rendering - Architecture - Materials - Jul 24, 2023

The user has a proposed fix for this in the case. FMaterialResource::IsDualBlendingEnabled needs the following modification that includes MaterialInstance check: bool bMaterialRequestsDualSourceBle ...

Crash in FPipelineFileCacheManager::RegisterPSOStats

UE - Rendering - Architecture - Oct 25, 2024

The game can crash when one thread clears RunTimeToPSOUsage while another thread is expecting it to contain a PSO it is registering stats for. Thread A:  calls CacheGraphicsPSO() Thread B:  calls C ...

Changing the scale of a single HISM instance greatly affects the LOD selection of all instances

UE - Rendering - Architecture - Sep 22, 2025

When using ISMs and HISMs, each instance can have its own transform, which can affect the LOD selection of one or more instances. For HISMs in particular, changing the scale of a single instance gre ...

FDetailGroup::AddGroup does not correctly apply the default expansion state for DetailGroups

UE - Editor - Verse Class Editor - Feb 10, 2026

There is a bug affecting DetailGroups in the engine. When adding child DetailGroups to a parent DetailGroup, the expansion state does not behave as expected and ignores the flags intended to control ...

RHIGetAvailableResolutions returns duplicate entries when bIgnoreRefreshRate is false

UE - Rendering - Architecture - RHI - Sep 17, 2015

When the RHIGetAvailableResolutions function fills the array that is passed in as the first argument, it will end up filling some slots with duplicate resolutions (including refresh rate) when the b ...

Failure while Cooking FOutputDeviceWindowsError::Serialize()

UE - Foundation - Core - Cooker - Mar 19, 2015

User receives an error while packaging. I haven't been able to reproduce this on my machine with templates I've created. Method to package: File > Package Project > Win64 The logs are attached. ...

Changing the mobility of an actor attached to a Skeletal Mesh in the level will change the mobility of the skeletal mesh

UE - Gameplay - Feb 16, 2016

Items attached to the Skeletal Mesh in the World Outliner can alter the Mobility of the Skeletal Mesh. Licensee specifically does not want to have any automated changes to asset mobility to happen ...

Console window is locked when casting to the player controller

UE - Editor - UI Systems - Jul 13, 2015

User has reported that access to the console window is locked when using this setup. ...

Material Parameter Collections are not working on Android v 5 phones from 4.11

UE - Platform - Mobile - Feb 9, 2016

Material Parameter Collections are not successfully passing stored values into Materials when packaged for an Android Phone with an OS version of 5. Both version 4 and 6, correctly use the MPC.Test ...

Crash when applying force on event tick to DM

UE - Simulation - Physics - Destruction - Jun 19, 2015

When using a DM and applying force via blueprints with event tick will cause a crash. Workaround: Using a timer instead will not cause any crash even with very low values. Crashreporter: [Link Re ...