On modern Mac computers with recent versions of MacOS (10.10 Yosemite or newer), there is a special virtual network adapter called awdl0 for the AWDL protocol (Apple Wireless Direct Link), which is used by Apple’s Airdrop and Airplay features. This virtual adapter constantly changes its hardware address, which makes the machine incompatible with the SOClass activation system, based on a hardware fingerprint.
To solve this problem we recommend disabling the AWDL adapter. The simplest solution we have found to date is a free utility called “WiFriedX”. You can find more details here and download it directly here. The sources are published on GitHub. The program is quite old, but it still works normally as of December 2019 and MacOS Catalina 10.15.2.
A nice side effect from disabling AWDL is that you immediately achieve better performance on the WiFi network, because the wireless adapter is no longer shared between your network connection and AirDrop.
A simple alternative to using a program is just to issue
“sudo ifconfig awdl0 down” before starting SOClass. But please have in mind that the interface refreshes itself on every reboot and maybe on other occasions as well.