Editor crashes on Mac when launching with the command -MacExplicitRenderer=0

UE - Graphics Features - Jan 19, 2017

Trying to launch the editor with the command -MacExplicitRenderer=0 causes a crash. At the time of the crash, the following line appears in the log:LogMac:Error: appError called: Assertion failed: A ...

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 ...

[CrashReport] Assertion failed in UE4Editor_LandscapeEditor!FLandscapeEditorCustomNodeBuilder_TargetLayers::HandleDragDetected()

UE - LD & Modeling - Terrain - Landscape - May 31, 2017

This report has been logged due to a high volume of submitted crash reports. Additional information is not currently available. User Descriptionsi create A game ENd Crashi was trying to create a l ...

[CrashReport] UE4Editor_Engine!FAnimNotifyEvent::IsBranchingPoint() [animtypes.cpp:86]

OLD - Anim - Aug 29, 2017

This is a common crash occurring in the 4.17 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 72 float FAnimNotifyEvent::GetDurati ...

ShooterGame Crashes on Exit on iOS Due to Exhausting Real Time Allowance

UE - Platform - Mobile - Jul 30, 2018

When closing ShooterGame on an iOS device, the application crashes due to "exhausting the real time allowance of 5.00 seconds". This issue is NOT a regression for //UE4/Dev-Networking as it is also ...

Indirect lighting samples incorrect if duplicated levels placed in same persistent level

UE - Graphics Features - Aug 29, 2017

Indirect lighting samples were not made correctly when building lighting with umap duplicated via the content browser and registering both source and destination as sublevels in one map. ...

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level

UE - Graphics Features - May 14, 2025

Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...

D3D HUNG crash with Aftermath result: CullLights

UE - Graphics Features - Apr 27, 2017

This is a specific subset of D3D HUNG crashes from [Link Removed]. This JIRA is for the crashes with the following results from Aftermath: [105]LogRHI:Error: [Aftermath] Status: Timeout [105]LogR ...

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. ...