Trying to view transient skeletal merged mesh crashes engine

UE - Runtime - Deformable - Mar 31, 2026

Using the Merge Meshes blueprint function within the Skeletal Merging Library. It does seem to work in that I see my merged mesh in a PIE environment, but if I double click on the transient mesh I g ...

Mutable: Child parameters hidden when intermediate Object Group uses "All Options"

UE - Runtime - Mutable - Mar 31, 2026

FCustomizableInstanceDetails::FillChildrenMap() unconditionally registers parent-child relationships via __ParentParamName metadata without verifying the parent exists in the active parameter list. ...

Mesh Reshape node with modified geometry from another skeleton explodes mesh.

UE - Anim - Mutable - Mar 31, 2026

Using the mesh reshape node with seperate meshes produces a broken mesh. An example project: Most if not all clothes will be originally made to fit the Average Male body. I'm trying to morph a tu ...

Control Rig + Animation in Sequencer Can Lead to Unexpected Slider Reset

zComponent - Archive - Mar 30, 2026

When a character has both a Control Rig track and an Animation track, interacting with any slider in Sequencer can be interrupted. ...

CSM Cached Shadows missing when changing FOV

UE - Rendering - Graphics Features - Shadows - Mar 30, 2026

When changing the camera FOV with r.Shadows.CSMCaching enabled, the cached shadows don't appear to be used and shadows are missing. This occurs because the r.Shadow.RadiusThreshold can be low enoug ...

Incorrect CRC hash for shared fragments with FInstancedStruct member

UE - Engine Scaling - Mass - Mar 30, 2026

User has encountered an issue with shared fragments that contain a member variable of type FInstancedStruct. It appears that UE::StructUtils::GetStructInstanceCrc32() does not correctly compute the ...

"Allow Sequencer Edits Only" and Control Rig performance impact

zComponent - Archive - Mar 27, 2026

We noticed an issue working in sequencer with "Allow Seqeuncer Edits Only" and control rigs. Performance will drop when manipulating using the AnimDetails channel sliders. ...

USD Export - crashes when sub level holds level instance

UE - Editor - Content Pipeline - USD - Mar 27, 2026

The engine is crashing when the user tries to export from a persistent level with a sub level that contains a level instance. ...

Level Sequence SpotLight USD Exporter Bug

UE - Editor - Content Pipeline - USD - Mar 26, 2026

The attributes for spotlights are not exported. ...

Renamed controls creating duplicate curves in sequencer that once fixed up cause selection issues.

UE - ACT Character - Control Rig - Mar 25, 2026

When a control is renamed after it has already been animated in a sequence, the control curve name map needs to be fixed up. Once it is fixed, selecting the control in the world will not map the sel ...