Sprite sheets cannot be reimported in 4.8 in a project that was converted from an older version

UE - Gameplay - Paper2D - Jun 11, 2015

User bug report: Why do you guys remove the Json Importer from UE 4.8? All atlases from TexturePacker can not be imported anymore on our projects. Is there a way to activate it? or maybe is there a ...

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 ...

Cannot export a Datasmith scene to the Unreal Engine project root folder on MacOS.

TM - Interoperability - Oct 29, 2024

This is mac specific. I could do the export normally on Windows with the same Twinmotion CL and UE version (5.5 preview).  It is also a regression specific to 5.5, since I've been able to export a d ...

Access Violation - UMovieSceneFolder::PostLoad - Accessing freed memory

UE - Anim - Sequencer - Sep 19, 2024

A licensee has hit an access violation issue due to a movie scene containing a reference to an invalid child object binding. It triggers in the following method: UMovieSceneFolder::PostLoad // Vali ...

Importing static mesh while a PIE session is running permanently breaks nanite on the asset

UE - Editor - Content Pipeline - Import and Export - Mar 12, 2025

Importing a Static Mesh during PIE can cause it to never enable Nanite, even if it reports that Nanite is enabled. To re-enable Nanite on the mesh, the asset needs to be deleted and imported again ...

HLSLCC crashed on parsing UAV related instruction

UE - Graphics Features - Oct 10, 2019

1.glsl_type with image was not fully inited with HlslName field set, causing the crash 2.seems many types of op are not support by current hlslcc, cause error msg. e.g. RWTexture2D.Load[Image Remo ...

Custom Nav Area Not Affecting Nav Mesh Until Restart

UE - AI - May 2, 2016

When using a Nav Modifier volume with a custom Nav Area class, the Nav Mesh is not being affected until the editor is restarted. Found in 4.11.2 binary. Reproduced in 4.12 Preview 1 binary and Main ...

Vignette in stereoscopic looks incorrect, entire frame as opposed to each eye

UE - Platform - XR - Apr 6, 2016

Vignette seems to be being applied to the entire frame instead of each eye in stereoscopic, creating a really strange effect in your peripherals when viewed through a HMD. Can also see this effect i ...

CrossCompileTool module fails to build due to missing include

UE - Graphics Features - Oct 24, 2016

The include for VulkanConfiguration.h was added to VulkanBackend.h, which is one of the external dependencies for the CrossCompileTool. This include is not complete however. This results in this mod ...

Building for Gear VR Distribution fails due to missing Oculus lib

UE - Platform - XR - Jun 7, 2017

Users have reported that building for Distribution on Gear VR results in failure due to a missing Oculus library. The error they receive is as follows: UATHelper: Packaging (Android (ETC2)): [javac ...