Avast 41227 update/online install error solution here !

Avast Free Antivirus / Premium Security
1

You may have broken DNS. Set DNS for 8.8.8.8 and 8.8.4.4 and then check.
Authors should consider workaround for this. Hardcode some IPs as reserve maybe?

2

In the paid versions you get SecureDNS/RealSite.