The layers you have selected contain more than one mesh. You may want to go back and import the meshes separately. If you continue, the meshes will be combined and a new boundary will be created.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.3.0.0 (25.3.0.0)
Syntax
C#
public static FailureDefinitionId TooManyMeshes { get; }