I've checked the official website and it appears that the software has been discontinued. I say this because the official website's DNS records indicate the domain expired and the hosting deleted, therefore making it impossible for you to download it, but luckily, with the Software Informer's help, the download was stored on the official's servers allowing to still have the possibility to obtain in.
Here is the page: http://rebol-view.software.informer.com/download/
Secondly, since the software has been discontinued, connection to the servers would be impossible at this time, therefore the errors you've received.