A TradosTag (TTX) file contains the full pathname of the original file that was used to create this file (for example the Microsoft Word file). This pathname is used when you preview the file, or you save the file into its original format. If the TTX file is moved to another computer (and so this pathname is no longer valid), then when you preview, or save the file to original format, the SDL Software will display the Save or preview native file wizard to find a suitable pathname.