Significant hitch occurs when invoking ApplySettings on a UGameUserSettings object

UE - Rendering - Features - Jun 18, 2025

Calling the ApplySettings method on a UGameUserSettings object results in a noticeable hitch, with severity proportional to the number of primitive components present in the scene. This hitch stems ...

Curve Atlas Row Parameter uses derivative ops when Texture Sample connected to curveTime input

UE - Rendering - Architecture - Materials - May 1, 2026

When a Curve Atlas Row Parameter node is used with a Texture Sampler connected to the curve time input, the sample type uses derivative ops. This has negative performance implications for Nanite co ...

[Level Instances] Editor Actor Folders does a full refresh after any LI is loaded, leading to wasted time when bulk loading LIs for a given WP region load

UE - Engine Scaling - Streaming - Level Instances - Jun 26, 2025

From Licensee: We discovered a pretty big performance hit in editor when loading level instances for a world partition map, specifically: EditorActorFolders.cpp:FActorFolders::OnAllLevelsChanged() ...

Attached actors have AttachmentReplication marked as dirty every net update

UE - Networking - Feb 11, 2026

In AActor::GatherCurrentMovement, bWasAttachmentModified will be set to true if the actor’s root component has an AttachParent, even if none of the values in the AttachmentReplication struct have ch ...

[CrashReport] Assertion failed: !PinRef->bWasTrashed - UEdGraphPin::SerializePin()

UE - Gameplay - Blueprint - Sep 8, 2017

This is a common and longstanding crash that has affected more than 200 users since at least 4.15. This crashGroup was previously associated with [Link Removed], but that specific repro case has be ...

Unable to PIE + Crash after editing SColorGradingPicker

Tools - Jul 26, 2017

Changing Color Grading settings of a post process volume and using "Enter" to commit changes prevents the editor from entering PIE / Simulate mode with the error message "Can't Play In Editor / Simu ...

"Override Function" search box in the Blueprint Editor does not match actual function name (only its display name)

UE - Framework - Blueprint Editor - Mar 5, 2024

This is a quality-of-life issue for UE users. The issue was also detailed by the UDN user in a video in the linked UDN case. The Blueprint Editor provides an "Override Function" functionality in th ...

Mover plugin: Crash on UFloorQueryUtils::ComputeFloorDist() and other utility functions that assume the pawn uses a UCapsuleComponent

UE - Runtime - Character - Dec 4, 2025

The following functions have been found to perform unchecked casts of the pawn's "UpdatedComponent" to class UCapsuleComponent, possibly resulting in crashes:UFloorQueryUtils::ComputeFloorDist()UGro ...

Possible data loss/corruption when loading levels in editor

UE - Gameplay - Jul 18, 2018

Reported behavior: Given Level_A which contains object_X, where object_X references Level_BDeleting object_X causes AssetRenameManger to check if we need to patch up other levelsLevel_B is load ...

Crash in RHICommandContext& GetContext() in Test/Shipping builds when bUseChecksInShipping is true

UE - Rendering - RHI - Nov 29, 2022

RHIinit() calls GRHICommandList.GetImmediateCommandList().GetContext() to make sure that GDynamicRHI->Init() initialized the immediate command list (by calling FRHICommandListImmediate::InitializeIm ...