Looks like there were some issues with our CDN in your region, can you please share information:
* when exactly this happened,
* IP of your server (or at least your network, like 55.55.55.x)
* IP of autoinstall-win.plesk.com (resolved from your server, you can get this using "ping autoinstall-win.plesk.com" for example).
This can help us to contact CDN vendor and discuss this issue.
Thank you.