Unable to create installation source

When I try to add this installation source I get this error message after 20-25 minutes: Unable to create installation source from URL 'ftp://ftp.mirror.ac.uk/sites/ftp.suse.com/i386/supplementary/KDE/update_for_9.1/yast-source'. Details: ERROR(InstSrc:E_no_instsrc_on_media) Try again? What does this mean? And what do I do to make this work? Thanks, Jerome