Thank you for the clarification. From what I have read online this error can occur if the connection information that the kfm is using does not work correctly. When you applied to to the page did you enable advanced file management? If in the HTML Editor wizard do you have a connection selected from the connection drop down?
If so what is the connection you have selected. In this connection how are you specifying the host? From what I have seen if you are using localhost and getting this error you might want to try updating the host in here to be 127.0.0.1 instead of localhost. Please check on these things and let us know the result that you get.
