leette Explorer | Level 4

As I said, I did try the process with different devices, different networks and different browsers. The process is always the same, this page still works: https://www.dropbox.com/out-of-space?oqa=account_menu_upgrade&reason=upgrade but clicking on any of the "upgrade now" buttons leads to a blank page. 

Thanks @Jay for getting back to me. I've tried different browsers, with and without institutional VPNs and on different devices, so it appears to be account related.