Acronis (18.0.6525) activation server unavailable?

Hello.

My Acronis True Image 2015 needs to be activated?
Using the login credentials, I just used to login into this forum, I get the error message, that the certification server is not available. I should check my internet connection or ...
See screenshot for mor details.

Is there a known issue? Or is our firewall blocking the connection? To what server is Acronis trying to connect?

Thank you in advance.

Cheers!