Texture Streaming can randomly streams in all Mips, causing large memory spikes

UE - Rendering Architecture - RHI - Dec 5, 2025

A possible race condition allows texture instance views to read uninitialized bounds, causing either garbage or zero screen size values to be returned by FRenderAssetInstanceAsyncView::GetRenderAsse ...

[CrashReport] UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() [kismetreinstanceutilities.cpp:1880]

UE - Gameplay - Blueprint Compiler - Oct 5, 2017

This is a somewhat common crash that has occurred throughout the 4.17 release. Users have not provided any description of their actions when the crash occurred. The callstack is similar to some ol ...

ResavePackages commandlet with Build Lighting applies level transform each time

UE - Foundation - Core - Cooker - Sep 13, 2016

While using the commandlet for RebuildPackages with -BuildLighting and having any sub-levels with level transforms will be added to the current position each time this commandlet is run. As an exa ...

Camera attached to a Spring Arm jitters when put at a +90 or -90 degree angle on the Y axis.

UE - Gameplay - Nov 18, 2016

When a camera attached to a spring arm is turned at a +90 or -90 degree angle in the Y Axis (can't go any further) and turned, it can jitter and cause visual issues. Note: This occurs in the base ...

Blueprint Library plugin set to 'Runtime' doesn't work in Standalone/packaged builds if used inside of the 1st Person Character BP

UE - Foundation - Cpp Tools - UnrealBuildTool - Nov 18, 2016

Blueprint Library plugin set to 'Runtime' doesn't work in Standalone/packaged builds if used inside of the 1st Person Character BP. User Description: Blueprint libraries are still broken in the fi ...

Orthographic Camera Preview window does not render materials

UE - Graphics Features - Jan 17, 2015

I am using the orthographic camera preview fairly extensively for making an in-engine Tiling Texture maker. This feature is currently busted since the orthographic camera preview window is rendering ...

Modulated shadows do not render in the correct area on older devices / versions of Android OS

UE - Platform - Mobile - Apr 5, 2016

This issue was reported by a user who was having issues with their modulated shadows showing up in random spots on their mobile devices. Their devices were a Samsung Galaxy Note 2 and a ASUS Zenfon ...

Cannot find source code error when doubleclicking blueprint nodes to see it in the code.

UE - Gameplay - Blueprint - Apr 2, 2018

The launcher version engine cannot find *.inl file from installed location (i.e. in my case it is located at D:\Launcher\UE_4.19\Engine\Source\Runtime\Engine\Classes\Kismet\KismetMathLibrary.inl) an ...

If user set ChunkID to a higher value, UpdateManagementDatabase will be very slow

UE - Gameplay - Sep 4, 2018

If user set ChunkID to a high value, the construction process of the database managed by AssetMAnager becomes very long. The cause is the following code in UChunkDependencyInfo :: BuildChunkDepende ...

Playrate / slomo causes motion blur length to change incorrectly

UE - Graphics Features - Jun 16, 2017

Discuss with the team what the actual desired behavior should be and adjust this calculation. This one is meant to stabilize the motion blur when we have a variable delta time but may be having kn ...