Unreal Engine Issues

ImportMeshPaintTextureFromVertexColors only works with "Per Instance Vertex Colors"

The "Import Vertex Colors" feature in mesh paint mode only works if the instance had vertex color overrides enabled. This is especially problematic for Nanite meshes since usually you can't add act ...

Object with "defaultconfig" cannot be edited in Project Settings if their config section exists in DefaultXXX.ini

FAssetFixUpRedirectors::FixupReferencers cannot be run silently

SFixupRedirectorsReport was added with 31698013. There is no way to prevent the UI from showing so the code cannot be used in unattended mode. ...

Color picker widget auto-closes unnecessarily

A licensee reports that the color picket widget in Unreal Editor closes whenever a blueprint actor (map placed instance of an actor blueprint) receives a property changed event, even if the change e ...

Viewport Controller Camera Control Regressions in UE5.8

In UE5.8 it appears some changes were made to the camera control and navigation in the editor viewports. You can no longer use controller and mouse simultaneously to control the camera. Previously ...

Resavepackages commandlet strips level package thumbnails

When loading thumbnails in FLinkerLoad::SerializeThumbnails, the level asset has two thumbnails. The first one has a size of 0, which causes the loading process to abort early. Since the actual thum ...

Cook Non-Determinism in USplineComponent

1. Non-Deterministic LastAuthority Serialization LastAuthority is assigned in USplineComponent::Serialize. Its value depends on the order in which the object and its archetype are serialized, leadi ...

Drag and drop does not work from a window created with PySide

The cursor position is no longer updated during drag and drop, so drag-over events cannot respond correctly. Commenting out the following code in WindowsCursor.cpp works as a workaround ( the behavi ...

In the level editor, when configuring a component that is part of an actor blueprint, adding entries to a TMap with C++ enum keys results in duplicate keys and an incorrect warning popup.

Note: This started happening in UE 5.4 and persists up to latest. It is probably related to [Link Removed] Closed ([Link Re ...

When Constrain Aspect Ratio is enabled, the display position of DrawDebug rendering becomes misaligned

Display DrawDebugSphere at the DefaultPawn's positionSet bConstrainAspectRatio=true on the DefaultPawn's CameraComponent Setting bConstrainAspectRatio=true in CameraComponent causes DrawDebug renderi ...