Google ads blocked

Question

After a Google search, if I click on the Google Ads links a security warning appears using any browser. 
 
 The Sophos SSL Certificate is not recognized and I can't view the page referred from ADS. 
 Any suggestion ? 
 
 Thanks in advance. 
 
 Firmware: SFOS 17.5.10 MR-10

Michael Dunn · Accepted Answer

From the "In Use" column I can see you are not actually using the "No Ads or Explicit Content" web policy. You are however using the Default Policy. 
 Assuming you haven't made any changes, the Default Policy blocks the User Activity "Suspicious". If you then go to the User Activity tab you see that Suspicious includes the category Advertisements. 
 
 So anything that uses a firewall that has a web filter policy of Default Policy will have Advertisements blocked. The way the XG blocks advertisements is with a block page served using its own CA. 
 If you do not want to block advertisements, the easiest thing is to add a rule to allow Advertising above the rule to block Suspicious. Alternately you can change the block Suspicious to a your own list of categories or even change the definition of suspicious. 
 
 You may also want to try clicking on the Log Viewer (top right corner) and then switch to Policy Test. That can be used to determine exactly why you are being blocked.