Invalid Argument Given URL is not allowed by the Application configuration.

After installation and configuration of facebook connect, I got the following error message, when I clicked the Facebook connect icon in my website login screen. Facebook User name and Password screen came up but the error message persists. Also, if I type my Username and password, nothing happens except the error message. Furthermore, nothing shows up when I click the Facebook tab in my profile. It is just empty. Help Please:

Invalid Argument Given URL is not allowed by the Application configuration.