ZenGarden or project with MSAA enabled crashes on iPhone 6 and 6+

UE - Platform - Mobile - Jul 19, 2017

Zen Garden crashes on the iPhone 6+ before anything appears onscreen. Occurred on: iPhone 6+ on 10.3.2 Didn't occur on: iPhone 6S on 10.3.2 ...

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 ...

Culling Distances Not Working For Static Mesh in Procedural Content Generation Tool and Foliage Tool

UE - World Creation - Procedural Tools - Mar 28, 2025

When creating Foliage or Procedurally Generated Content the culling settings of the Static Meshes do not apply correctly. As soon as either a minimum or maximum cull distance is set the Static Meshe ...

iOS Shipping Build using std::thread crashes on launch

UE - Platform - Mobile - Jun 2, 2017

A user is reporting that using the following code in a GameMode class causes shipping iOS packages to crash on launch:void ANOGSSDKGameModeBase::StartPlay() { std::thread([](){ std::clog << "THRE ...

Create Session does not work in a packaged game from any project that has used C++

UE - Networking - Dec 28, 2015

After adding C++ to a content-only project, Create Session no longer works in a packaged game. The following warning appears in the log: LogScript:Warning: CreateSession - Invalid or uninitialized ...

Crash when Playing in Mobile Preview with Capsule Direct Shadows

UE - Platform - Mobile - Jul 15, 2016

When Capsule Direct Shadows are enable, attempting to play in Mobile Preview will cause the preview to crash. ...

"There is an enum property of type 'ECollisionChannel' with an invalid value of '(INVALID)" warning when opening Level Blueprint

UE - Gameplay - Dec 13, 2016

REGRESSION Yes, does not occur in 4.14 at CL 3232073. When opening the level blueprint, the user sees the following warning in the output log:In asset 'None', there is an enum property of type 'EC ...

[CrashReport] USpeedTreeImportFactory::FactoryCreateBinary()

UE - Editor - Content Pipeline - Import and Export - Sep 19, 2017

This is a common and longstanding SpeedTree import crash that has occurred since at least 4.14 for over 100 users. This seems to be the same issue as a previous Jira from 4.10 which was closed wit ...

Physics Constraint Actor: When plasticity is enabled, Drive Position Target is reset to zero on constraint initialization

UE - Runtime - Simulation - Mar 5, 2026

When a Chaos joint constraint is first created, having linear/angular plasticity enabled will unexpectedly force its linear/angular drive position target to zero on initialization, disregarding the ...

Mobile Previewer: Safe Zone Invalid Until Window Resize

UE - Platform - Mobile - Jul 12, 2021

When the Mobile Previewer loads, the Safe Zone widget is not working properly at startup, and requires a window resize to update to the correct Safe Zone. ...