MakeMKV cannot extract all the episodes from the DVDs, are they corrupt?

I've seen dvds that don't have separate episodes vob files-just a giant vob blob (ha ha funny). What you need to do is use an old program called DVD Decrypter in the ifo mode. What you'll get are a bunch of small vob chapter files-then you need to determine how many chapters are in each episode. You then use mkvtoolnix to combine the chapters into individual episodes. If it sounds complicated it really isn't but you really have to pay close attention or you'll make a lot of fuckups. Best to do some searching on the internet to learn how to do it.