I have been getting this error recently and am not sure why. When trying to save a drawing i'm working on, i will randomly get this error that the drawing is in use (but i'm the only one with it open). I'm not sure if this has to do with a server/network problem or if it's an ACADE problem, but it's really becoming quite a hassle as it happens at least once a day. The error tells me that it saves it as a TMP file, which i can go and rename later as the file i was trying to save it as, but the file i was working on becomes locked somehow for sometimes as much as 10 minutes, and i cannot move it to another folder or save it or anything. Any thoughts on to what would be causing this or possible solutions?? Thanks in advance for the help. I've attached a picture of the error message i'm getting.