Bone names of ~100 characters or longer crash the editor when baking to control rig

UE - Anim - Rigging - Control Rig - May 15, 2025

This is an issue with inconsistencies over rig names and how control names are generated. We expect that a control name will be appended with _CONTROL or _CURVE_CONTROL. But because URigHierarchy: ...

Texture color encoding (sRGB) issue

UE - Texture - May 14, 2025

There seems to be a regression with linear textures (commonly for multi-channel masked textures) in UE5.4. Setting the "Encoding Override" (under Texture > Advanced > Source Color Settings) to "Line ...

Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level

UE - Graphics Features - May 14, 2025

Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...

ResavePackages commandlet (buildlighting) fails/asserts on reflection captures in non-visible sub-levels

UE - Graphics Features - May 13, 2025

When building reflection captures through the ResavePackages commandlet, it frequently triggers an ensure inside of ReflectionEnvironmentCapture.cpp. If distributed shader builds start causing prob ...

Meta Quest - Visual Artifacting in right eye with Lumen enabled and effects quality set to High

TM - VR - May 9, 2025

Reported in SF [Link Removed] On Meta Quest headsets, when Lumen is enabled for VR, setting the Effects Quality to High can cause visual artifacts to appear in reflections in the right eye of the h ...

PIE Seamless Travel with a standalone level instance causes assert in UWorldPartition::BeginDestroy

UE - World Creation - Worldbuilding Tools - Level Instances - May 8, 2025

This check is hit on the server instance while it is performing garbage collection during the seamless travel. During this garbage collection, it will determine that the UWorldPartition object belon ...

Actor Channel failure occurs when quickly unloading and loading a streaming level

UE - Networking - May 8, 2025

With high enough latency, quickly unloading an reloading a streaming level with a replicated actor on the server can cause the actor channel on the client to fail to find this actor: UActorChannel:: ...

SKP Import - Applied texture maps from previous Twinmotion versions are lost after reimport in TM 2025.1.1

TM - Interoperability - May 8, 2025

Reported in SF [Link Removed] For SKP imports that were added to a file in a previous version of Twinmotion, when the .tm file is concerted to and opened in TM 2025.1.1, if the SKP model is re-impo ...

Assertion failed in FNetGUIDCache::CleanReferences during seamless travel after reloading primary asset package

UE - Networking - May 7, 2025

Following this sequence of events, the ObjectLookup and NetGUIDLookup on the server's PackageMapClient will end up in a bad state. In the ObjectLookup Map, the primary asset's package will be mapped ...

AssetRegistry: In a packaged game ScanPathsSynchronous with bForceRescan=true will permanently forget about assets inside IOStore containers

UE - Foundation - Data Pipeline - May 7, 2025

This came up from several discussions on UDN and internal discussion. The root cause is that the AssetRegistry currently cannot discover packages inside IOStore containers, it relies on the seriali ...