Do you have the following in your local.config file setup?
/* FSFK Settings
Your FTP Server, and path to the lib/images folder (from where the FTP connects from), IE
ftp://phpvms.net/phpvms/lib/fsfk or ftp://phpvms.net/public_html/phpvms/lib/fsfk
You want the path from when you connect to the FTP down to where the /lib/fsfk folder is
SECURITY NOTE! Make a separate FTP user and password ONLY for this, with access only to this folder
*/
Config::Set('FSFK_FTP_SERVER', '');
Config::Set('FSFK_FTP_PORT', '21');
Config::Set('FSFK_FTP_USER', '');
Config::Set('FSFK_FTP_PASS', '');
Config::Set('FSFK_FTP_PASSIVE_MODE', 'TRUE');
Config::Set('FSFK_IMAGE_PATH', '/lib/fsfk'); // web path from SITE_ROOT
If your images are not uploading you could have issues here.