I was getting this same error and could not find a fix anywhere, but it turned out that the error was related to the way I tried to use the plugin.
If you use the methods of the facebook plugin through window.facebookConnectPlugin, you will no longer see the error, and it will work fine, trying to access the methods of the plugin through the FB or CDV.FB object, you will get an error, and everything will just not work for you.
Not sure if this will help you, but you are the only person I saw sending the same error and that I circumvented it, so hopefully this will work for you too.
source share