Garbage Collection Causing Noticeable Hitches

UE - Foundation - Core - Apr 11, 2016

Garbage Collection is causing noticeable hitches on whatever interval it is run on. This is noticeable in the UE4 Profiler, as you will see a spike every X amount of seconds, depending on how often ...

Setting size of GameViewportClient gives different results on Android than in Editor

UE - Platform - Mobile - Feb 9, 2017

Setting size of GameViewportClient gives different results on Android than in Editor OpenGL ES renders with the viewport origin in the bottom left, so that's potentially related to the problem. A ...

World Outliner selection does not update transform widget location during play

Tools - May 23, 2017

World Outliner selection does not update transform widget location during play. This issue can be easily fixed simply by reselecting the object, this issue only affects the first time the object is ...

AssetManager can load blueprints of the wrong type when redirectors exist

UE - Gameplay - Sep 29, 2017

The logic in the AssetManager to determine if a scanned Blueprint should be added to the primary asset directory is wrong if that blueprint has an active redirect targeting it. The simplest way to r ...

[CrashReport] Mac crash - UE4Editor-SlateCore.dylib!SWindow::IsVisible()

UE - Platform - Apple - Oct 12, 2017

This is a trending Mac crash coming out of the 4.18 previews. Most of the project titles experiencing this crash mention "AR" It is the exact same callstack and crashgroup as [Link Removed], but th ...

fbx attribute curve import do not support correctly tangent at the start end end of the curve

UE - Editor - Content Pipeline - Import and Export - Sep 2, 2020

We are not reading all the key flags and we do not import correctly start key and end key tangent. I create a shelve but this is not the complete fix, we must do this only if we do not have fbx ket ...

Copying collapsed graph with a node with a custom Exec pin results in duplicate pin name

UE - Framework - Blueprint Editor - Aug 17, 2022

When duplicating a collapsed blueprint graph which has a node with a custom Exec pin, this results in blueprint compilation error that a duplicate named pin is found. Duplicated exec pins aren't ass ...

FAnimUpdateRateParameters::GetInterpolationAlpha appears to be returning an invalid value for TrailMode

UE - Anim - Aug 5, 2023

It appears that  FAnimUpdateRateParameters::GetInterpolationAlpha is not returning a sensible value when running in TrailMode.  Currently the only variable in the calculation is EvaluationRate which ...

Switching project monitor with shift+win+arrow keys

UE - Rendering Architecture - RHI - Apr 24, 2025

Using Windows+Shift+Arrow keys to move the application window in Windowed Fullscreen from a low resolution monitor to a high resolution monitor does not resize the application window on a Windows 10 ...

FInstancedStruct member uproperties are not cached when "Generate Optimized Blueprint Component Data" is enabled

UE - Framework - Blueprint - Nov 18, 2025

A licensee has encountered an issue where their FInstancedStruct isn't being gathered into CachedPropertyData when "Generate Optimized Blueprint Component Data" is enabled. The changes in [Link Remo ...