Latest image for MacOS supports Sierra and up. El Capitan is no longer supported
I tried running the 30.0.0 disk image on a MacBook running on El Capitan. It showed the following error:
Last login: Sat Jan 5 13:40:21 on ttys007
MacBook-Pro-XXXXXX:~ xxxxxx$ /Applications/MKVToolNix-30.0.0.app/Contents/MacOS/mkvtoolnix-gui ; exit;
Sorry, "MKVToolNix" can not be run on this version of macOS. Qt requires macOS 10.12.0 or later, you have macOS 10.11.6.
logout
Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.
[Process completed]
Can you please update the description on your website and in the README.macOS.txt