"Revit was unable to identify any rooms. If you are sure that rooms have been created in the project, please check the Project Phase setting to verify that the Project Phase matches the phase in which rooms have been defined in your project. "
Hello, as far as I know, you do not necessarily need the staircase in iesve software since it's just a simulation software. The main aim usually are the energy, lighting, ventilation simulations which are not affected by stairs. Also, if you notice, iesve do not have staircase making option in the ModelIT.
