Cause: You are trying to export a Revit file that is already open in another session, or the family editor is active. Solution: Close all other Revit instances. Ensure you are in the main project environment, not editing a family (e.g., a door or window).
Before exporting, configuration is essential. Users can access "Navisworks Settings" or "Global Options" to define: autodesk navisworks exporter download
This usually occurs after a Revit update or if the exporter version mismatches the Revit build number. Cause: You are trying to export a Revit