www.makemkv.com

I have a bunch of DVDs where attempting the "backup" function to make an ISO fails. The error message is simply "Backup failed", no other helpful info, even when using makemkvcon in debug mode.

However, if you do a normal rip, ripping every single title to an mkv file, even if you include every single stream, the rip succeeds.

What might cause that?

I believe there's a silent bug or the supposed error is not being printed. I've gotten this on several UHD discs with makemkvcon. I've ripped the same discs again and have not received the error. Furthermore the file hashes are identical between the rips, so I simply ignore the error if the reading completes :-/

Unfortunately in my case the backup isn't successful, it bails out before it gets to the end of the disc.