Updates to DesiredFocusWidget for a UserWidget are not propagated to existing instances of it inside the WidgetTree of other widgets

UE - Editor - UI Systems - Nov 17, 2025

This issue has been reproduced in UE 5.3 to 5.7 and source versions. A repro project is available. Below are the findings from an initial investigation of the problem. Normally, when a UserWidget p ...

Adding "_API" specifier to FMovieSceneTrackEditor results in linker errors

UE - Anim - Sequencer - Feb 7, 2017

Unable to add API specifier to FMovieSceneTrackEditor, results in compile errors (pasted in the callstack field) ...

[CrashReport] UE4Editor-D3D12RHI!FD3D12Viewport::PresentChecked(int) [D3D12Viewport.cpp:492]

UE - Rendering - Architecture - RHI - Mar 29, 2019

Callstack is garbage past D3D12 calls but logging for visibility. Generated from CrashReporter ...

Bug in CurveLinearColor makes colors of Diffraction material white outside curve range, causing rendering artifacts

UE - Texture - May 14, 2025

There seems to be a regression with linear textures (commonly for multi-channel masked textures) in UE5.4. Setting the "Encoding Override" (under Texture > Advanced > Source Color Settings) to "Line ...

StableSpringsSystem has lots of warnings

UE - Simulation - Visual - Apr 6, 2026

System successfully compiled with 16 warnings. /Engine/Generated/NiagaraEmitterInstance.ush:2732:250: note: variable 'OutMaterialMultiplier' is declared here void SolveDistanceSpringMaterial_Emitter ...

Extreme hitching when using profile command (stat startfile) + other stat commands

UE - Foundation - Core - Apr 19, 2018

Running the "stat startfile" command in a 4.19 project causes constant editor hitching. Running the same command in a 4.18 project does not produce any hitching by comparison. ...

When using Lighting Scenario, loading order will affect how it's applied to the instances

UE - World Creation - Worldbuilding Tools - Foliage - Mar 7, 2019

When using Lighting Scenario, loading order will affect how it's applied to the instances, resulting in corruption if content is loaded after the lighting scenario ...

Orthographic Rendering - Lumen Reflection Artefacts

UE - Rendering - Architecture - Apr 28, 2023

Mutable custom versioning issue from 5.5->5.6

UE - Anim - Mutable - Sep 19, 2025

In 5.6, a handful of new entries in `FCustomizableObjectCustomVersion` were added, including `SetDisplayNamePropertyAsPinNameOfTableNodes`. Looking back at the history, `SetDisplayNamePropertyAsPinN ...