I can't activate parallels toolbox. When I enter a key, it says the key is in use. I haven't change my machine. I just upgrade to Mac OS Mojave recently. "Activate on this machine" option doesn't work. Please help. + Parallels support system doesn't work. I chose Telegram option for support, since no other option works, and the Telegram bot asked me to create a ticket. I did, but at the very last page, it asks me to input "Support Code," which I don't know where to find.