In case you are seeing the error after following the e-mail confirmation link, which looks like this:
First, you need to log in to your Personal Area, and then after you are logged in, kindly try to open the e-mail link from your e-mail again. Please, kindly be reminded that your Personal Area and e-mail both should be opened in one browser.
Also, if you requested confirmation link several times, we recommend you to wait for some time (about 1 hour), then request the link once again and use the link that will be sent to you after your last request.
If the issue persists, please, kindly make sure you have cleared your cache and cookies beforehand. Or you may try using a different browser.