A permanent solution is to disable "Webguard" in Avira then you can view ads without issue. To disable webguard do the following:
1. Double-click the Avira umbrella icon on the desktop, to start AntiVir.
2. Click on the + sign next to Online Protection
3. Click on Deactivate for AntiVir WebGuard
Another solution would be to uninstall Avira (as long as you didn't buy it) and install Microsoft Security Essentials, it's a free anti virus program from Microsoft that integrates itself very well into the operating system and works in the background not showing any annoying popups.