makemkvcon 2.0.0 segfault from blu-ray ISO

[DavidGA]

makemkvcon 2.0.0 (Linux, Flathub) segfaults when opening any Blu-ray from files (ISO or folder). Physical discs and DVD ISOs are fine

After the Flathub package updated from 1.18.4 to 2.0.0 (commit 1aa1825c), makemkvcon crashes with a segmentation fault (exit code 139) whenever it opens a Blu-ray from files. This happens with makemkvcon -r --noscan --minlength=0 info iso:/path/disc.iso on every Blu-ray ISO I tried, and with info file:/path/folder on an extracted Blu-ray folder. It dies about a second after starting, without printing an error. The last messages are "Using direct disc access mode" for an ISO, or "Opening files on harddrive" followed by "AACS directory not present, assuming unencrypted disc" for a folder. The flags don't matter (with or without -r, --noscan, --minlength), and --debug=<file> doesn't write a log before the crash. The sources are decrypted backups made with makemkvcon backup --decrypt. A folder written by 2.0.0's own backup crashes too, so it isn't limited to backups made with older versions. Removing the MAKEMKV/ metadata directory from the backup doesn't help either.

On the same system, these work normally: info disc:99 drive scans, info dev: on physical BD, UHD and DVD discs (LibreDrive), info iso: on DVD ISOs, and backup --decrypt disc:N from a physical Blu-ray (I only ran it partway, but it produced decrypted, playable streams). Rolling back to 1.18.4 (flatpak update --commit=ba1b0921…) fixes it: the same ISOs open fine and give the same title list as before.

Environment: Debian 13, kernel 6.12, Flathub com.makemkv.MakeMKV (KDE 5.15-25.08 runtime), LG WH16NS60 and ASUS BW-16D1HT drives. I only tested makemkvcon, not the GUI.

[jerrac]

I've been getting segfaults when trying to load backups (not isos, what MakeMKV creates for blu-ray/uhd when you use the 'backup' option) via the gui for the past few weeks.

Your tip about it working for discs is also true for me.

I believe it started when I upgraded Ubuntu to 26.04, then I upgraded makemkv to 2.0.0, but that didn't fix anything.

In my case I'm compiling it myself according to the topic in this forum.

Ubuntu's bug report tool seems to indicate some odd memory issues, but it doesn't let me copy the actual data out, and then it doesn't try to report because it's a compiled app. Super useful that.

Running `makemkv` from the cli doesn't really add any extra output.

Any other ideas on how to get useful data for bug reports?

[fgmccabe]

Me too. I had to downgrade.

[SamSpeexy]

I tried freemkv (linux version) and it works well for converting ISO's (encrypted or decrypted) to MKV and other formats as long as your disc is in the keydb.cfg file.
www.freemkv.org

For ripping actual discs, it doesn't hold a candle to MakeMKV yet.