Unloading level during PIE leads to editor crash

Tools - Dec 6, 2017

Unloading level during PIE seems to lead to an editor crash. Most easily reproducible by enabling malloc stomp. ...

Copy-pasting an actor property that is a set of strings adds extra quotes and escapes

UE - Editor - Workflow Systems - Aug 24, 2025

Copy-pasting an actor property that is a set of strings adds extra quotes and escapes. The licensee has reported: The problem doesn't happen for example for properties of types set of integers, nor ...

Ensure triggered when creating Scene Proxy for GroomComponent

UE - Rendering Architecture - RHI - Apr 30, 2025

When a room component is added in C++ via the actor constructor, an ensure is triggered from precaching and the groom component. Behavior also observed on UE5/Release-5.5, CL: 40988944 ...

ARSharedWorld, AREnvProbe, and ARSaveLoad fail to build for iOS with clang error

UE - Platform - Mobile - Jul 18, 2019

ARSharedWorld fails to package at the build command for iOS with the following messages. Packaging (iOS): [1/4] sh /Volumes/Storage/Workspaces/Release/Samples/AR/ARSharedWorld4.23/Binaries/IOS/ARS ...

[CrashReport] Mac crash - FCocoaRunLoopSource::Process

UE - Platform - Apple - Sep 14, 2017

This is a somewhat common Mac crash that has occurred since at least 4.14 and into 4.17. Users have not provided any descriptions of their actions when the crash occurred. The callstack contains l ...

[CrashReport] UE4Editor_LevelEditor!SLevelViewport::SaveConfig() [slevelviewport.cpp:2019]

Tools - Sep 6, 2016

This JIRA is being entered as a result of it being one of the top crashes in 4.13.0. Error message: Access violation - code c0000005 (first/second chance not available) Source Context: 2004 ...

[CrashReport] Crash related to refreshing Destructible Mesh - SaveExistingSkelMeshData()

UE - Simulation - Physics - Destruction - Jul 20, 2017

This is a common crash affecting users in 4.16. User DescriptionsPressing the button to restart the basic mesh in the destruction editor causes the crash.Refreshing a Destructible Mesh that has had ...

New VR-Basic level triggers Metal validation layer assertion

UE - Platform - Apple - Mar 16, 2020

This was discovered externally and reported on UDN here: https://udn.unrealengine.com/questions/563268/mac-editor-crash-when-disable-ambient-occlusion.html ...

'Missing Receipt' error after disabling plugin in binary build and repackaging

UE - Foundation - Cpp Tools - Oct 18, 2018

This was originally found with Android Launch On but also occurs Launching on to Windows with a new project. This will not reproduce when using a build from PerforceogPlayLevel: Setting up ProjectP ...

Project breaks if Online Subsystem plugin is disabled

UE - Foundation - Core - Apr 25, 2017

Disabling Online Subsystem prevents the project from loading. On Windows, this produces an error shown in attached screenshot. On Linux, this causes a crash with the attached callstack on project ...