I use a VPN with IP Address located in JP everytime I go to DLSite. I was able to purchase games via my VISA card many time before, but recently when I try to buy some games with the same card I've been using, the webpage gets stuck on the verification page (some link starts with https://api.veritrans.co.jp) and stays there forever. I tried several methods, including changing VPN addresses, switching different wi-fi or browsers, and rebooting the computer. None of these methods work. Also, I tried to used the same VISA card to purchase stuff at different websites, and the transactions were all successful. I really have no idea why it does not work now.