Canvas Render Target 2D doesn't get alpha mask when rendering with ES3.1

UE - Platform - Mobile - Apr 23, 2020

The Alpha Mask on a Canvas Render Target 2D no longer appears when rendering with ES3.1. This is a regression from 4.24.3 (CL-11590370). This was reported and tested in 4.25 Preview 7 (CL-12759524) ...

Inventor Assembly imports incomplete or missing geometry

UE - Editor - Content Pipeline - Datasmith - Importer - May 22, 2020

It seems that UE4 has a problem with importing Inventor Assemblies and Subassemblies. Files are either the wrong orientation or missing their geometry completely. This was reported and tested in 4 ...

Crash compiling a blueprint after changing a TMap value from Vector to Vector4

UE - Foundation - Core - UObject - Jun 29, 2020

REGRESSION: Issue does not occur in 4.24 Crash occurs when the user changes a blueprint TMap value from Vector to Vector4 and then compiles the blueprint. This seems to only occur with TMaps, as ...

Static lighting isn't bouncing when using Layered Materials

UE - Graphics Features - Lumen - Aug 13, 2020

Static lighting will not bounce on the ceiling when using a Layered Material. The Material Attributes Layers node is used which doesn't appear in 4.24.3 so this isn't a regression. This was report ...

Absolute World Position post process no longer works in mobile preview

UE - Platform - Mobile - Sep 2, 2020

User reports this work correctly in 4.24, but now no longer works as expected in 4.25.I don't have a clear CL just yet, marking unconfirmed. If you change the settings to use ES3.1 Preview and just ...

Crash when attempting to deform a landscape when Paint Layer has not been used - Assertion failed: !TargetProxy->HasLayersContent() || !InCanUseEditingWeightmap || EditingLayerGUID.IsValid() [LandscapeEdit.cpp Line: 5252]

UE - LD & Modeling - Terrain - Landscape - Sep 9, 2020

The editor crashes when attempting to draw a weight blended texture to the landscape if it hasnt been used on that landscape yet. This crash can be completely avoided if the stone texture is painted ...

Niagara Crash : ExportParticleDataToBlueprint module causes buffer overrun

UE - Niagara - Aug 10, 2021

This buffer overrun is probably caused by the ExportParticleDataToBlueprint module does not respecting the GPUAllocation Fixed Size setting in the module. In fact, out-of-range export data is not c ...

Atmosphere related scan line artifacts for Path Tracer with MGPU

UE - Graphics Features - Path Tracer - Feb 10, 2023

There are two UDNs related to this issue.  It makes the Path Tracer unusable with MGPU, with atmosphere enabled. I already have a one-line fix implemented and tested.  The atmosphere scan line arti ...

Ensure in GatherSubobjectData

UE - Gameplay - Nov 27, 2023

An ensure in GatherSubobjectData is being hit under certain inheritance conditions. This appears to be similar and potentially related to [Link Removed] and the fix at CL 16377852. Stepping through ...

Serialized Blueprints containing MIDs do not load correctly in packages.

UE - Rendering - Architecture - Materials - May 8, 2024

This issue is an easy fix but raises a different problem which is likely ingrained in UE, which is that MIDs should not be serialized out and should always be transient. Unfortunately we are in a po ...