I have a user who's trying to open Unigraphics files in ProE. He claims he was able to do this before. The UG files use the same extension as ProE, .prt. When we try to open these files now, it gives an error: "To Open unigraphics file, you must select the 'Unigraphics (*.prt)' filter." However, when I look in the list file types on the 'open' dialog box, Unigraphics is not listed. Is this 'filter' installed separately? I never saw this work myself, but the user claims it worked only a couple of weeks ago.