Thank you for all your suggestions! It used to work and then suddenly it stopped working. I use Safari on my mac. I even tried Google Chrome and Opera, but the results were the same with Error 522. As of today, I was able reach the web site, but only some data were loaded, leaving blank...
It appears that Topping site has been down for a while now. I was not able to access it for a few weeeks since. Anybody knows what might have happened to Topping as a company?