The error from the original post is related to DNS. If you have the same error, then using a VPN should allow you to bypass it.
DNS related errrors are difficult to find the cause for. It could be as simple as having to reboot the router, to having to change entire settings for your network. Or it could even be your ISP that's causing the issue by blacklisting the server. (Comcast is a known ISP that blacklisted the update server.)