So I have a certain bluray disc from 2010 that I'm trying to rip in its entirety because I happen to think menus and extras can be pretty interesting. MakeMKV includes the functionality for achieving this. Unfortunately, MakeMKV consistently chokes on this disc some 15% into the process.
So there's an alternative method suggested: Copying the encrypted files over and then letting MakeMKV do something with those. Fine. I copied the files over. It took rather longer than MakeMKV looked like it was going to take, but it worked nonetheless. I also found the remaining steps: Let MakeMKV take an non-decrypted stab at the disc, abort the process, and copy the discatt.dat file over to my personally copied files.
So far so good. But here's the snag.
Apparently, the only thing MakeMKV can do with a discatt.dat file is make MKVs out of the individual videos. That's exactly what I was trying not to do here. I want the decrypted BDMV in its entirety, so I can get the menus and such.
Last resort: I made an ISO out of the files I'd copied from the disc, mounted it, and tried to use MakeMKV to create an decrypted "backup" of it. This time, MakeMKV quickly gave up, complaining about AACS errors. According to what I've read, AACS errors only come about due to MakeMKV not being up-to-date with its AACS codes. But that clearly cannot be the case, if I'm using a MakeMKV from late 2019 on a bluray image from 2010.
Stumped.