Are you on a TOR connection?
I experienced that yesterday when I tried to access the site on a TOR connection.
I played just few minutes ago, completed a challenge, but did not receive the same message. I'm using a standard browser on a standard connection that time.
I'm not even familiar with TOR, I'm using default connection from my ISP. I guess I need to use VPN to fix this which is the same as what I did in the past when similar issue happened.
Just a reminder, they also have a raffle for players that will be able to complete at least 20 gift boxes out of 24, so if you are planning to partake, secure a box within 5 days from now.
Thanks for the reminder, I'll try to find a way to fix the above issue first before depositing for the promotions. I wish I will be able to participate on time so I wont missed the raffle for those who are able to complete the 20 gift boxes.