Several people have run into issues with firewalls and routers suddenly blocking traffic from the *proseries.com domain. A way to test is by clicking/typing in this link in a browser on your machine:

https://prodldfp.proseries.com/pro/patches/2020/release/w_eng_core.inv

If it doesn't work and you get something like the message below, something on your computer (FireWall, Anti-Virus, Anti-Malware) or your router / modem / isp is most likely blocking files from our domain. Check your firewall settings, restart your router, etc.