Exterior siding does not display correctly in 3D or in elevations.

[GHArchitect]

I am using Chief Architect and all of a sudden, the exterior finishes on elevations and 3d camera views have disappeared. But not the whole wall, the studs,Exterior 3D view with siding not displaying correctly..pdf insulation and furring still show up. The siding has not disappeared completely. On the exterior 3D I still see horizontal and vertical strips of the siding. Finishes on the interior elevations and 3d cameras are fine.