We have started using draft sight over autocad, opening drawings up,editing and saving them. We went to open a drawing today as normal and it said drawing file needs recovery, proceed?, we clicked yes and it just opens a blank drawing? we tried opening it back in autocad and it says drwaing file is not valid?? please help as this drawing took many days and is needed asap? P.s everything is saved on a server. I have attached the drawing for you to look at.