My ProSeries was not updating and the (actually pretty good) tech support person determined that for some reason, something was not allowing ProSeries to access proseries.com. This was preventing updates.
We explicitly unblocked the site via Windows Firewall and my anti-virus, nothing.
We looked at my router's firewall, nothing.
Finally, I figured it out. I have my DNS set for Cloudflare DNS server of 220.127.116.11--this DNS apparently thinks the Proseries.com has "malware". (Insert your own joke here)
Anyway, by changing my DNS server setting in my Ethernet port properties from 18.104.22.168 back to 22.214.171.124,
I am sure many would say well, "Why set it that way in the first place?" it's for safer computing.
Anyway, just sharing in case it helps the next lost soul.