Good day. After intstall of ARTIO JoomSEF I am getting an Error Message in my Joomla backend : Error loading datafeed.

Also, I am unable to change any setting in Global Configuration because the "SAVE" and "APPLY" buttons have completely dissapeared.

Also, I am unable to see any of my ARTICLES or add new ARTICLES in the ARTICLE setion - it says Error on Page. Please assist, I really appreciate if anyone can give me some advise.