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 (2.9.7.7) 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: