Same for me, I bought Black Shark 1 (download) and the Black Shark 2 upgrade and I can't get either one to activate. I get the message "Unable to connect to the activation server. Check your Internet connection and try again." The Star Force method of activation doesn't work either, it says the website is down.
Ticket submitted, #19508, but I haven't heard anything back yet.
I'll admit it, I downloaded the cracked versions of Ka-50 Black Shark and A-10C to test them (no demos available as far as I know) and it's really, really frustrating when it's so much easier (as in, effortless) to get those pirated versions running than it is to use the legitimate paid versions of these sims. I've now spent hours trying to get my paid version of Black Shark running and if it isn't sorted out soon I'm just going to charge back my credit card purchases for Black Shark 1 and 2 and use the pirated versions, which work flawlessly.
DCS, I want to give you my money for these sims! Please find some way to make it easier for your paying customers to activate your products, this is ridiculous.