Unreal Engine Issues
Unreal Engine Issues
Mobile Previewer: Content Scale Factor 0 Issues
UE - Platform - Mac - Jul 13, 2021There are several reported issues with Save Zones displays in the mobile previewer when the Mobile Content Scale Factor is set to 0. When MobileContentScaleFactor is set to 0 a couple things hap ...
Asset values change when the Editor is out of focus when using Maya or Web Browser
Tools - Jul 18, 2018When switching between any open software (Maya, web browser) and UE4 while Simulation is running, sometimes the values change on the asset and it starts to oscilate between <-0.6,0.6> or any other s ...
Users project crashes when opening level that loads multiple sub-levels
UE - Foundation - Core - UObject - May 31, 2017Users project crashes when opening level that loads multiple sub-levels. Unable to reproduce this in a clean project so the users project is provided though Epic's box account (link is in the repro ...
TMap does not serialize properly in specific circumstance when it contains a UObject property set to null by default
UE - Foundation - Core - Aug 8, 2018A TMap containing a struct with a UObject reference property (set to nullptr by default) does not serialize properly for an instance where the UObject reference is set on the instance, but the TMap ...
Niagara color picker user parameter preview no longer updates until confirmation
UE - Rendering - Architecture - Niagara - Apr 18, 2025Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...
Noise Material Expression is rendering outside Min and Max Range with High Position Values
UE - Graphics Features - Mar 31, 2015The Noise Material Expression is rendering values well outside the Min and Max Range set in the Expression node. Also Reproduced in Main Promotable-CL-2469752 Alerted the user to suspicions and su ...
VS fails to compile when USTRUCT is referenced as BlueprintReadWrite or BlueprintReadOnly
UE - Foundation - Cpp Tools - UnrealHeaderTool - Aug 22, 2017Defining a FBoneReference variable as BlueprintReadWrite or BlueprintReadOnly in the UPROPERTY macro fails to compile in 4.17. The error message provided by VS states: LogCompile: Error: Type 'FT ...
Material parameters flickering due to UMG animation switching and multi-threaded execution
UE - AI Workflows - UI Systems - UMG - May 12, 2026When continuously transitioning to UMG animations that have a track targeting the same material parameter within the UUserWidget::OnAnimationFinished event, the number of source inputs to UMovieScen ...
GenerateProjectFiles.bat fails to compile UnrealBuildTool when VS2019 is the only version of Visual Studio installed
UE - Foundation - Cpp Tools - Apr 1, 2019Attempting to run GenerateProjectFiles.bat on a computer that only has Visual Studio 2019 installed (no other versions of Visual Studio were ever installed previously) will fail to compile UnrealBui ...
Linux: Assertion at splash screen when trying to open UE4Editor
UE - Platform - Linux - Mar 21, 2017I ran into this while looking to verify [Link Removed] at CL 3355923. I logged the issue I was verifying the fix for last night and have not updated anything locally, so the "OpenGL 4.3 not supporte ...