www.makemkv.com

Encountered a problem while trying to convert to MKV file with a certain Blu-Ray title : "ELYSIUM".
After the process finished a warning came up that a number of chapters failed to convert.
Using another method like making a backup of the Blu-Ray "ELYSIUM" also had errors.
When playing back the Blu-Ray BDMV folder with Mac Blu-ray player the playback stopped somewhere in the beginning of the second chapter.

Is it normal that certain titles cannot be converted with Makemkv?

This reminds me of the old story about Microsoft Windows for Cars, which would suddenly cause the car to stop, displaying a "GENERAL CAR FAULT". It could mean you were out of gas, the engine blew up, or the radio lost the lock on the station.

Without logs, it is impossible to say what happened.