Revit :: Model Lines On Elevation

I am in the process of drawing up an existing building and firstly am setting up with the building mass. I have managed to get the main bodys of the building done and the main roof.The problem now is that when i switch too the east or west elevations to add mass for the roofs on the adjoining wings of the building it wont let me see the model lines when i draw them in the screen i just get an error message " None of the created elements are visible in Elevation: East View. You may want to check the active view, its Parameters, and Visibility settings. "I have my reference line set not far from the building and it seemed fine when i done the roof from the north and south views for the main building. I can see the model lines when i switch too 3D views but i cant create the mass from there.