Hi,
Have you checked your spam folder? Ususally Arturia support respond within 24 hours unless it's weekend or holliday.
I think i have read a post like yours before in the forums. Keep in mind this forums is'nt Arturia support.
ASC 2.4 require OS 10.13+. Perhaps that's your issue.
Try download and install ASC version 2.3 instead. It's for OS 10.10+ or perhaps version 2.1 if the OS 10.10+ for version 2.3 is a typo. Uninstall ASC 2.4 completely first.
Hopefully ASC will not update it self to version 2.4, when it's not for your OS.
You can download from here, when you click the Show Archives button for asc.:
https://www.arturia.com/support/downloads&manualsI don't use MAC or Live.