[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 ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

Linux crashes in the Project Browser without using the -nocef command

UE - Platform - Linux - Feb 22, 2022

When opening Unreal Editor on Linux, the Project Browser opens but is completely unresponsive. Shortly afterwards the editor will crash. If you use the -nocef command when opening the Editor, everyt ...

ResavePackages commandlet (buildlighting) fails/asserts on reflection captures in non-visible sub-levels

UE - Graphics Features - May 13, 2025

When building reflection captures through the ResavePackages commandlet, it frequently triggers an ensure inside of ReflectionEnvironmentCapture.cpp. If distributed shader builds start causing prob ...

[CrashReport] Access Violation - UModelComponent::GetPhysicsTriMeshData() [modelcomponent.cpp:673]

UE - Simulation - Physics - Oct 2, 2017

This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred. The callstack is similar to [Link Removed], which was ju ...