In the 'Files to Backup' window an icon representing each file is displayed to the left ot the file name. If a file cannot be found a warning icon is displayed. It may be that you have deleted the file, in which case the file should also be removed from the backup group. It could also be that the file has been accidentally deleted, in which case you may want to restore the file from your backup. The warning icon will also be displayed if you have moved a file In this case, remove the entry from the 'Files to Backup' window and add the file again from it's new location.