Copying LOTR 4-Disk Set, Last is too large?

Lord of The Rings - The Return of the King. I succeeded in backing up the movie (2 disks) and the first of the two extra discs. DVD Fab Decryptor ( did copy the last to HD, but it’s 6.7g, hmmm… little too large, methinks. Anyone else had this issue? I wuold like to back up this disk as well. Thanks in advance… :bow: