LOD glitch when using Control Rig with Import Skeleton node

UE - ACT Character - Control Rig - Aug 26, 2025

In Unreal Engine 5.6 and Main, a glitch occurs when switching between LODs in a character setup that uses a Control Rig to dynamically load the skeleton hierarchy through the Import Skeleton node in ...

After Seamless Server Travel, the Client cannot move the character or see the Server character

UE - Networking - Jul 9, 2015

After Seamless Server Travel, the Client cannot move the character or see the Server character. On the Server, the Client character appears to be falling in place. Tested in both first and third per ...

Editor mode keyboard shortcuts active when in Play In Editor

UE - Editor - Jun 20, 2025

Editor mode keyboard shortcuts active when in Play In Editor. This behavior is a departure from previous versions. It was described by the licensee as confusing and it clashes with gameplay assigne ...

Instanced Properties create temporary references on child objects in Blueprints

UE - Gameplay - Blueprint - Nov 29, 2017

When an object whose class has the EditInlineNew specifier is added to an instanced property, any children of the blueprint will have a reference to the same object that was created for the instance ...

[AI] StateTreePropertyRef does not have option for Promote to Parameter

UE - AI - StateTree - Nov 5, 2025

I got a report from one of my designers that since we took 5.6, they have been unable to see the "Promote to Parameter" options when attempting to bind an output from one of our common tasks. I took ...

UClass::SparseClassDataStruct null at editor-time for child blueprints until compile

UE - Framework - Blueprint - May 29, 2024

Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...

Packaged Project with Media Player Asset 'From Memory' Crashes and Corrupts Project

Tools - Feb 9, 2015

There is no Callstack associated with this crash. And I was unable to reproduce this in main due to a known issue when switching the 'Stream Mode' to 'From Memory'. When packaging a project in 4.6. ...

DynamicMaterialParameters Niagara module resets write flags on emitter update

UE - Rendering - Architecture - Niagara - Feb 4, 2026

When using the DynamicMaterialParameters Niagara module in UE 5.6, 5.7, and UE5-Main (CL 50298778), updating an emitter causes Boolean values, such as Index0Float0Write, to reset to default values, ...

Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.

UE - Engine Scaling - Streaming - World Partition - Aug 19, 2025

Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...

[CrashReport] Mac/Metal Intel compiler crash - UE4Editor-MetalRHI.dylib!CreateMTLRenderPipeline()

UE - Graphics Features - Oct 27, 2017

Mark S: This is an Intel compiler failure on macOS 10.12.6. Callstack from LogAssertion failed: [File:/Users/build/Build/++UE4+Release-4.18+Compile/Sync/Engine/Source/Runtime/Apple/MetalRHI/Privat ...