Rip this

Years ago, I ripped most of our DVD collection to .mp4 files. It's fine, but it's not a complete record of what was on the DVD (which will never matter but still irks me) and doesn't have subtitles which I'd sometimes like. So I'm working my way through again, making .ISO backups with MakeMKV and then .mkv files. One in a great many won't backup and I haven't worked out yet if it's a media problem or a recording problem. Have to buy another copy to test that, I guess.