Facebook returned an unexpected error: [Error occured at line 693]

i have been using the plugin very well for about two months, now i have this issue in the line 693

// Error detection:

        if (array_key_exists('errors', $response))

                throw new FacebookUnreachableException(!empty($response->errors) ? array_pop(array_pop($response->errors)) : '');

        $json_response = json_decode($response['body']);

        if (is_object($json_response) and property_exists($json_response, 'error')) {

                throw new FacebookUnexpectedErrorException((is_object($json_response->error) and property_exists($json_response->error, 'message')) ? $json_response->error->message : '');

        }

http://wordpress.org/extend/plugins/facebook-page-publish/