Cast enum to byte could occasionally break cook/resave in level BP

UE - Gameplay - Blueprint Compiler - Aug 27, 2020

 Workaround:The blueprint macro had a cast from the enum to an int and that was causing the issue, getting rid of the cast and just returning the enum and then changing all the places that were usin ...

Import FBX Camera with 90 degree rotation

UE - Anim - Sequencer - Aug 15, 2016

The FBX Import into Sequencer currently assumes that the camera has a rotation axis of 0, -90, 0. This assumption shouldn't be there. For example, currently this works: 1) From Sequencer, export a ...

'Get Distance Along Spline At Spline Point' Causes Crash

Tools - Jul 28, 2018

User reports that the reason for the crash is that because UpdateSpline is false on the AddSplinePointAtIndex blueprint node, this line is never called [ReparamTable.Points.Reset(NumSegments * Repar ...

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 ...