Firewall blocking client Application

Dear Members,

I have fortigate 310B firewall installed. We have block unwanted websites through url filtering option.

It is working fine. We are using Wrench client software, but when i enable URL filtering option it block the wrench client application. it shows error: unable to get default server details. please check the login name and default server. The operation has time Out.

But when i disable the URL filtering option it works fine.

can any one suggest me, what to do.