There has been some confusion around our drag and drop functionality which we are updating in future builds. Currently, only Sketchup and OBJ files work with our Drag and Drop launcher. In order to access Revit files in Prospect, you will have to open them using Revit and use our add-in in order to send your models to VR.
The screenshot above refers to this add-in which is automatically installed once you download and install Prospect on your desktop. The add-in is referenced the image below.