I have been having a recurring problem with Sharefile. At first, I thought it was an AutoCAD 2016 vs 2018 compatibility problem, but I get an additional error when that is the case. Something about Sharefile won’t let save a drawing more than one time. Second and third attempts to save the file prompt this error that one or more objects cannot be saved in this specific format. If I save the drawing to another location (other than Sharefile), it will save. I then have to reload the dwg back to Sharefile. It is very annoying.