I have been developing a workbook that includes multiple pages, multiple macros, functions, calculations, formatting, etc. During the devlopment process, I have saved two versions so that I always have a good back up. All of a sudden the file name changed - at the end of the file name (after the ".xls"), [Group] appeared. I do not know what this means, why it happened and how to get rid of it. I also have no idea what other effects it will have on my continuing development. Can you help me out with this one?