My site has been whitelisted and I’ve had no trouble with Twitter Cards in the past but today I’ve been having problems.
When I attempt to validate the card it says: “Unable to render Card preview” and the log says
ERROR: Fetching the page failed because it's denied by robots.txt.
My site is: http://illustrationchronicles.com
I have no access to robots.txt but I’ve checked it and it looks ok.
Older pages that were tweeted with cards are now also no longer validating.
The page I am trying trying to validate now is: http://illustrationchronicles.com/Al-Hirschfeld-Broadway-s-King-of-Caricature
Many thanks for any help you have.