I am getting above error while starting SDL SmartTarget 2011 SP1. Please assist me..
That error message is shown if it cannot connect to the Fredhopper URL configured in SmartTarget.xml (in TRIDION_HOME\web\SmartTarget).
So double-check that the URL is correct and that the Fredhopper instance is up and running.
Looks like your fredhopper is stopped hence you are getting this error. Try after starting deployment agent and your indexer service.