Hi there. I dont know what I did, but I saved my a couple days ago, and all was fine. Opened it now, and cannot see anything in the top view. I see all of my info in the other 3 viewports, but the linework will not show up in Top. I tried zoom extents, and shows me the grid with nothing on it. When I try to draw a new line in the top view, it shows me a prohibition symbol (red circle with a slash it) and will not let me do anything.