Unable to render Card preview


Hi, I am getting an error in Card Validator can you advise how to correct this please.

INFO: Page fetched successfully
INFO: 11 metatags were found
WARN: Not whitelisted



Good news! Have solved this myself by looking at the page source code. For some reason the correct meta tags were not being added to my home page. Twitter cards work perfectly on other pages and posts, I am guessing its something weird with my theme so I can live with that.
Anyone with similar problem (and a novice like me) might try checking the page source code also.