Unreal Engine Issues
Unreal Engine Issues
Material Instance Platform Stats don't update when Material Layer parameters are changed
UE - Rendering - Architecture - Materials - Oct 14, 2025The instruction count appears to update properly if the whole asset editor is closed and reopened. ...
User-defined InstancedStaticMeshComponent subclass misbehave in SCS Editor
UE - Framework - Blueprint Editor - Oct 13, 2025Context Users can create InstancedStaticMeshComponent (ISMC) (blueprint) subclasses. Any ISMC class can be added to an actor blueprint. When a mesh is selected and transforms are added to the Insta ...
Actors transforms broken in cooked builds when their parent is an IsEditorOnlyActor
UE - Framework - Oct 7, 2025When creating a hierarchy of Actors in the Outliner, the transform of the "child" actors will be reset if their Parent's IsEditorOnlyActor property is true. The project in the EPS case is using ...
HZB Occlusion causes large stalls on the render thread
UE - Rendering - Architecture - RHI - Oct 7, 2025HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...
Vertex color does not work on Skeletal Mesh with Nanite enabled
UE - Rendering - Graphics Features - Nanite - Oct 7, 2025Nanite enabled skeletal meshes don't work with materials containing a vertex color node. The vertex color material does work for non-Nanite skeletal meshes and Nanite-enabled static meshes. ...
Converting a mesh to Nanite merges mesh sections with the same material index, but with different material overrides
UE - Rendering - Graphics Features - Nanite - Oct 6, 2025When a mesh with multiple sections which point to the same MaterialIndex but have different settings enabled (e.g. bCastShadow is enabled on only one section) is converted to Nanite, the material sl ...
TMaps do not function as expected in the details panel when then TMap variable is in a blueprint component
UE - Framework - Blueprint - Oct 3, 2025The default element can be added multiple times and changing the value from the drop down. ...
Values for InitialOnly replicated arrays can fail to be captured in replay when removed and re-added between checkpoints
UE - Networking - Oct 2, 2025When the first checkpoint is recorded, the correct array properties will be captured in the LifetimeChangelist. When these array items are later removed and another property on the actor is changed, ...
FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code
UE - Niagara - Scalability - Oct 1, 2025Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...
OnTextChanged not called for UEditableTextBox / UMultiLineEditableTextBox when text is set programmatically
UE - Editor - UI Systems - Sep 29, 2025When calling SetText() on a UEditableTextBox or UMultiLineEditableTextBox, the OnTextChanged delegate is not triggered. This regression was first reported in UE 5.3 and acknowledged previously in UD ...