I am not sure what file you are speaking of, however, I will let you know a few things about R12, and in particular LISP. If you are attempting to write information to a lisp file, but you cannot seem to do it more than once, it may be because you have not properly "closed" the file you were writing to. The only way to close a file once you have lost the file handle is to close AutoCAD. If the file you are attempting to open is a drawing, search for and find a file with the DWK extension. Those are files that "lock" drawing files under R12. If there are no files open, and AutoCAD is not running on any computer connected to the network, check the network node name on the station you are using, it may be interfering with the network node name of another user. Also check the status of the # of authorized users, in some subversions of R12 it was possible to set the number of authorized users to 0. You may also need to close the network license manager software then restart it. A corrupted *.PWD file occasionally causes this error as well. I have tried to tell you all of the common reasons a file would show as "open" when it was not open, however, without more specifics from you, I cannot be more accurate with a diagnosis.