This error "UNABLE TO CALCULATE ROUTE, NO ROADS NEAR STARTING POINT"comes
when Nuvi cant see any maps : no roads, no route. And Nuvi use basemap when can't find route on detailed map, so I guess also your basemap isnt available or may be you're so off road and nuvi can't find any road to start calculation-
Weird situation-

Edit :look at your map list and check if maps are available