I recently upgraded the Router firmware in a clients 2820n to v3.3.4, which includes the additional functionality and the external Web Content Filter service.

Didn't make any changes to the firewall set-up, left it as it was originally configured by me, with certain options the client wanted like blocking Facebook, Bebo, BBC's iPlayer, Youtube etc..etc..

Since the update if they click on marketing links within certain e-mails, that go off to an external web site, they get the following error: -

"The requested Web page has been blocked by Application Enforcement (CSM)."

I have never seen this type of error before when going to a "blocked site" and they also get it if trying to go to certain dictionary sites, like http://www.askoxford.com or http://dictionary.cambridge.org

They also get blocked with the same error message when going to http://www.yell.com !!!

None of these sites have been specifically blocked by me in the Firewall, so I'm at a loss as to what is causing the problem, as the error message doesn't seem to help or give me any pointers, as "Application Enforcement" doesn't appear to relate to anything within the Firewall and these problems didn't occurr before the Firmware was upgraded.

Any help or ideas from anyone please....

Me too please. I am getting this error and don't know what on earth it is referring to.