VerboseCookerWarning warnings: Saving object into cooked package %s which was created at cook time, Object Name UniqueObjectNameForCooking_0, Full Path %s, Outer class %s

UE - Foundation - Data Pipeline - Cooker - Jun 19, 2023

Creating objects at cook time that are exported into the cooked package is a possible cause of indeterminism, and therefore we have banned it in engine classes and will fire a warning about it. Cur ...

Level Instance Property Override: Actor::Tags overridden pre-CS but clobbered by RerunConstructionScripts with no post-CS re-apply

UE - World Creation - Worldbuilding Tools - May 4, 2026

Summary When using the Level Instance Property Override system, overrides applied to `AActor::Tags` are silently lost for Blueprint actors whose Construction Script assigns or appends to `Tags`. The ...

Per object shadows, Error: FMatrix::InverseFast(),

UE - Graphics Features - Nov 13, 2015

LogUnrealMath:Error: FMatrix::InverseFast(), trying to invert a NIL matrix, this results in NaNs! Use Inverse() instead. LogOutputDevice: === Handled error: === Ensure condition failed: false [File: ...

[CrashReport] UE4Editor-CoreUObject.dylib!UPackage::Save() during COTF

UE - Foundation - Core - Cooker - Nov 21, 2017

This is a common Mac crash that has occurred since at least 4.17.1 User DescriptionsJust trying to launch my project on any output I can. No luck.launching AR project on IOS device. Ugg. Last adjus ...

[CrashReport] UE4Editor-ApplicationCore.dylib!FMacWindow::ApplySizeAndModeChanges()

UE - Platform - Apple - Oct 27, 2017

This is an early trending Mac crash in 4.18. Users have not provided any descriptions of their actions when the crash occurred. Callstack from LogLogAssetRegistry: Asset discovery search completed ...

[CrashReport] Mac Metal crash - FSceneRenderer::RenderDistortion()

UE - Graphics Features - Aug 29, 2017

This is a somewhat common Mac crash occurring since 4.15 and into 4.17.1. Users have not provided any descriptions of their actions when the crash occurred. This specific callstack was previously ...

GAS: Async loaded GameplayCueNotify can execute cue events out of order

UE - Gameplay - Gameplay Ability System - Mar 22, 2025

Licensee reported problem via UDN. Context GameplayCues ('cue') are events that can be fired by game code, that are identified via a GameplayTag. Cues can be instantaneous or can be a state on any ...

[CrashReport] Mac crash - FShaderCompilingManager::ProcessCompiledShaderMaps()

UE - Graphics Features - Nov 16, 2017

This is an infrequent Mac crash in the 4.18 release. The callstack is a match to [Link Removed] (loading Zen editor on Mac), but that was confirmed fixed for 4.18.0 while this continues for users. ...

Open Level Crash in Gear VR

UE - Platform - XR - Oct 5, 2016

Projects using Open Level (blueprints) or ServerTravel (in C++) will crash the application once it's open on a device using Gear VR Mode. 10-05 18:01:46.451: A/art(19619): sart/runtime/check_jni.cc ...

[CrashReport] Linux crash - FMonitoredProcess::Launch()

UE - Platform - Linux - Sep 14, 2017

This is an infrequent Linux crash occurring in 4.17.1. Callstack from Log[2017.09.06-15.26.30:028][666]LogLinux: Error: appError called: Assertion failed: Assertion failed: [File:/home/***/.local/ ...