Get Mouse Position Blueprint node returns different values outside of viewport depending on whether it was called from Event Tick, or within an Actor function

UE - Gameplay - Nov 15, 2018

There seems to be a discrepancy between the output of Get Mouse Position node depending on whether the node is inside an Actor function or called from Event Tick. If the node is present inside a fun ...

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 ...

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 ...

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 ...

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. ...