Welcome the Technical Support section. Help us in assisting you by providing us with a concise and descriptive elaboration of your issues. Be specific and if possible, provide us with a step-by-step instruction in replicating your problem.
Please you follow and re-read again this documentation carefully for how to setup the FB app documentation.jomsocial.com/wiki/Setting_up_Facebook_Connect, I am sure you did not set it properly.