CodeMix requires libgconf-2.so.4 that is not installed on Ubuntu 18.4
Exit value: 127
Nor is the library bundled with CodeMix.
/codemix-engine: error while loading shared libraries: libgconf-2.so.4: cannot open shared object file: No such file or directory
Sorry you're seeing this. It seems that package isn't installed in Ubuntu 18.04 by default, as it was with Ubuntu 16.04. You can correct this by installing the package with:
sudo apt install libgconf-2-4
You may need to restart the OS to have this work. Apologies for the inconvenience and we'll get that fixed.