Cant validate twitter card on one of four sites


We are a publishing company and have successfully validated twitter card on 3 of our sites - but one refuses and we can’t see why.
the validator seems to work fine, and we have to request approval - then we get an email saying that the metatags didn’t validate!
an example url is:

There are no clues in the tag validator - please help?


Yay - we got it sorted.
We had to reduce the description tag to under 200 characters. While that is in the instructions, the validator was giving a green light on the description tag anyway.
if this is an approval criterion, it would be good to make the validator validate it - would have saved us loads of time.


Sorry for the confusion, and we’ll take that feedback to the engineering team.