Crash when Undoing the change to a default class setting for widgets

UE - Editor - UI Systems - Sep 25, 2017

The editor crashes when trying to undo a default class change for a child widget after that widget has been compiled. This did not happen in 4.16, it appears to be a regression. ...

Data Tables can no longer import numeric enum values

Tools - Nov 1, 2017

Some changes to UEnumProperty::ImportText_Internal prevent this importing the stringified number (which is a float) as an enum value. This affects the JSON importer, and maybe the CSV one too. ...

Cannot add a non-static custom thunk to a code class

UE - Foundation - Cpp Tools - UnrealHeaderTool - May 7, 2018

In 4.19, it is no longer possible to create a non-static custom thunk in a class. This was possible in 4.18.3. REGRESSION: Yes. ...

Niagara module scripts "Map Get" node displays the 'Module' parameter as "Input"

UE - Niagara - Mar 9, 2020

The module parameter in a niagara module script displays the incorrect name Tested: 4.24.3, 4.25P, 4.26 ...

Deterministic cooking issue caused by ParticleModuleTypeDataGPU

UE - Niagara - Jan 18, 2021

This problem is similar to the following case. [Link Removed] [Link Removed] It seems to have been fixed in 4.16, but the licensee reported it in 4.25. ...

Property Coloration isn't supported for Nanite

UE - Graphics Features - Nanite - Sep 11, 2023

Property Coloration View Mode is not supported by Nanite. (Left cube is Nanite and isn't affected by the Property Coloration view mode) [Image Removed] ...

Adding Images: The image header is unrecognized

RC - Editor - Feb 14, 2025

This issue occurs only on Windows 11 24H2, but it affects all RealityCapture versions on this OS. It is allso not possible to open the images with the Windows Photos App.  ...

Changing the “DistanceField Trace Distance” requires rebuilding the lightmaps

UE - Graphics Features - Feb 18, 2025

Changing the “DistanceField Trace Distance” requires rebuilding the lightmaps even though the valu never affect light baking process in Lightmass. ...

Video material broken on Mac

TM - Rendering - Oct 21, 2025

On Mac devices, the video material in the viewport will display incorrectly, appearing stretched significantly. This only seems to affect the viewport and not rendered exports. ...

[AI] SmartObject with Precondition in a persistent collection crashes editor when exiting PIE

UE - AI - SmartObject - Sep 26, 2023

Adding the Precondition to the SmartObject caused an assertion when it was part of a persistent collection. The precondition needs to be able to pass its Activate method to cause the assert. This b ...