Intermittent crash in CacheOptimizeIndexBuffer on Editor startup on Linux

UE - Platform - Linux - Nov 16, 2015

Building 4.10 from the GitHub release branch on Linux fails to open after install and instead crashes User Suggested Fix: Switching triangle order optimization off with r.TriangleOrderOptimization= ...

UMG/Slate scroll bars have a minimum size for scaling

UE - Editor - UI Systems - Mar 14, 2017

A user has reported an issue about scroll bars having a minimum size in UMG and Slate code, causing them to not scale correctly when the scroll box is at a smaller size. This affects both horizontal ...

widget shows up solid white on iOS

UE - Platform - Mobile - Jul 24, 2017

The web browser widget does not appear to load correctly on iOS. It appears as a solid white block. This has been seen on: iPhone X, v11.4 (A11 Bionic) iPhone 6, v11.4 (A8) It did not occur on a ...

[CrashReport] Linux crash - FVulkanCommandBufferManager::WaitForCmdBuffer

UE - Graphics Features - Aug 22, 2017

This is a semi-common Linux crash coming out of 4.17.1. It is spread among a few different similar callstack affecting a handful of users. [Link Removed] [Link Removed] [Link Removed] [Link Removed ...

ARCore failing to package

UE - Platform - XR - Sep 26, 2017

Users reporting packaging issues with ARCore plugin enabled in 4.18 preview #1 and #2: https://answers.unrealengine.com/questions/709840/418-android-packaging-fails-with-arcore-plugin-ena.html ...

Compiling after adding a StaticMesh Component to a Child Blueprint of a Parent Blueprint causes the inherited StaticMesh Component to disappear

UE - Gameplay - Blueprint Editor - Oct 5, 2017

The Inherited StaticMesh Component in a Child Blueprint of a Parent Blueprint disappears when compiling the Blueprint. Regression: Yes Occurs in: 4.17.2, 4.18(Preview), and 4.19(Main) Does not o ...

[CrashReport] UE4Editor_SlateCore!SWidget::ExecuteActiveTimers() [swidget.cpp:986]

UE - Rendering Architecture - Materials - Dec 15, 2017

User comments:right mouse button in material editor made engine crash....becomes slow and crash....64gb ram, 2 xeon and gtx690....need to restart computer to everything works fine. need a solution t ...

Welded grandchildren do not overlap properly when their grandparent is simulating physics

UE - Simulation - Physics - Jun 7, 2018

Grandchildren (C in an attachment hierarchy of A < B < C) that are auto welded have issues related to overlap events when moving via physics. They tend to overlap later than they should. This does n ...

Web browser widget does not receive input when used in a 3D widget component on Android

UE - Platform - Mobile - Jul 9, 2018

Web browser widgets to not receive input when used in a widget component on Android devices Update: Oculus Quest devs attempting to implement and interact with the web browser widget via widget i ...

Adding Instances to a Hierarchical Instanced Static Mesh causes crash

UE - World Creation - Worldbuilding Tools - Foliage - Jul 29, 2018

Adding Instances to the Hierarchical Instanced Static Mesh Component on BeginPlay causes the Editor to crash. Tested in 4.19.2 (CL - 4033788), 4.20.1 (CL - 4229980), 4.21(CL - 4235929) ...