This option allows FenestraPro for Revit to analyze Conceptual Mass models created in Revit. Click on Concept Design on the Revit menu. Click on this dialog window that opens. A message will advise that you should select the mass for analysis. The mass that is to be analyzed should then be explicitly selected in the Revit Model since there may be several separate Masses in the project (surrounding buildings/urban context etc).
There are also buttons on this window for logging out of the application and to link to this Support Site for assistance.