Unable to render Card preview

[awwcutelol]

I have submitted a number of url for Twitter summary card validation and I keep receiving the “Unable to render Card preview” error. Any ideas as to why?

Here are a few of the url’s submitted:

http://awwcutelol.com/2015/03/18/aww-cute-lol-people-photo-roundup-march-18-2015/

http://awwcutelol.com/2015/03/17/uptown-funk-danced-to-on-a-treadmill/

[awwcutelol]

I should add that there is no log error either. Here is the meta data that is from the first link:

I’ve tried many plugins for Twitter cards and none seem to work, although this one seems to work fine on another site of mine.

Any help would really be appreciated!