Can't Open Sonic Pi 3.1.0... Error

Hi everyone
Hi Sam

I am encountering the same problem on our brandnew Mac minis running Mojave. I am trying to setup a master with SonicPi running to clone 25 student Macs.
Posted the error as suggested here on github:

Rebooting doesn’t help.
Plugging earphones doesn’t help.

Thanks for any help or hints!
Swissmorgy