I've got internet connection already, and the clock is pretty accurate. But I still get this error message.

It translates:
Please connect to the Internet and retry.
Either your computer is offline or the clock on your computer is set incorrectly, causing a connection error. An Internet connection is required. Please connect to the Internet or adjust your clock and try again. If this continues, ask 'Customer Support' for more helps.
It's after I downloaded the 30-days trial version of Acrobat DC on Adobe website and successfully installed that I got this message. It asked me to log in for the activation and It required me to rearrange the internet connection for it. I can swear that my connection and clock cannot be more descent than now. I checked everything to be fine and even tried every single step of troubleshooting stuffs provided on https://helpx.adobe.com/x-productkb/policy-pricing/activation-network-issues.html only to find nothing to be changed. Can you find out what can be the source of the problem?
