Structs cause packaging to fail when Blueprint Nativization Method is set to "Inclusive"

UE - Gameplay - Blueprint - Apr 26, 2017

Structs cause packaging to fail when Blueprint Nativization Method is set to "Inclusive" Note: Appears to be a regression (worked in 4.15.1) Error example: UATHelper: Packaging (Windows (64-bit)) ...

Project does not cook with actors containing ModularSynth component

UE - Audio - Sep 11, 2017

A project does not cook with actors containing ModularSynth component. The error is a follows UATHelper: Packaging (Windows (64-bit)): Cook: LogWindows: Error: begin: stack for UAT UATHelper: Pack ...

CLONE - Project does not cook with actors containing ModularSynth component

UE - Audio - Sep 13, 2017

A project does not cook with actors containing ModularSynth component. The error is a follows UATHelper: Packaging (Windows (64-bit)): Cook: LogWindows: Error: begin: stack for UAT UATHelper: Pack ...

MRQ render with a slow output format drives Niagara GPU tick flush into its dummy-view path, causing an access violation in SetShaderParameters

UE - Rendering - Architecture - Niagara - Aug 18, 2026

Sorry for the AI ticket, but it did a better job than I could: Rendering a level sequence through Movie Render Queue crashes the editor with an EXCEPTION_ACCESS_VIOLATION when the scene contains a N ...

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited in the Details Panel after an Editor restart

UE - Framework - Blueprint - Dec 9, 2024

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited i ...

Linux crash upon opening maps in Soul: City content pack

UE - Graphics Features - Jan 29, 2018

Opening the maps from the Soul: City asset pack on Linux causes a crash. This seems to be rendering related. It was originally reported as a Vulkan specific issue but we've reproduced it without Vul ...

Lighting behavior is unreliable for translucent lit materials, results are inconsistent depending on the editor camera's FOV and the editor viewport's width/height/aspect

UE - Rendering - Architecture - Oct 27, 2024

When working on the level editor viewport or testing on PIE, the visual appearance of additive/translucent lit materials changes significantly (and abruptly) when varying the camera FOV or the viewp ...

Same-named variables of other classes listed as references in blueprint

UE - Gameplay - Blueprint - Aug 14, 2015

If a variable in a blueprint is the same name as a referenced variable from another blueprint, using "find references" on the local variable will return references to both the local and the external ...

Material attribute layers issue with texture sample and VT lookups

UE - Rendering - Architecture - Materials - Nov 14, 2024

When using material attribute layers in a material layer setup, there is a potential discrepancy in the number of VT Lookups presented in the material instance's Platform Stats. When the same textur ...

Blackboard decorator node does not abort lower-priority nodes

UE - AI - Feb 16, 2026

When a branch of a selector is deactivated, all auxiliary nodes and observer delegates are removed. If the branch is reactivated soon and the CurrentActiveNode remains unchanged, the behavior tree l ...