www.makemkv.com

MakeMKV v1.8.12 win(x64-release) started
The new version 1.9.0 is available for download at /download/
Using direct disc access mode
This disc uses newer version of AACS protection. Please let us know about it by visiting /a/?DAwMDAwENNdsv5...
The volume key is unknown for this disc - video can't be decrypted
Failed to open disc

Try downloading and using that latest version (1.9.0 as of now). It seems to be working for me.

jyik01 wrote:MakeMKV v1.8.12 win(x64-release) started
The new version 1.9.0 is available for download at /download/
Using direct disc access mode
This disc uses newer version of AACS protection. Please let us know about it by visiting /a/?DAwMDAwENNdsv5...
The volume key is unknown for this disc - video can't be decrypted
Failed to open disc

There's a clue in there somewhere....