Tungfa,

yeah, I downloaded the 2.6.4 dmg file and installed the app, than I allowed it to open (at system preference) and when I double clicked on the icon it appears to run but than nothing happens. I already had Electrum-DASH 2.4.1 and since it don't allowed me to connect with my Trezor to validate it, I was waiting for this new release for a long long time...luckily I did a backup before installing the new version because I had to recover to my previous version after the new version didn't work.

Do you know if is there a way do (apt-get upgrade) from the terminal?