why meta description not showing up via yoast ?

I unable see meta tags column in the admin interface since 2-3 days , even today i was unable to see meta tags column ..i have yoast installed in the website.
I have attached screenshot of how its looking like.
can anyone tell why is this happening ?

Check your Yoast is updated to the latest version (14.0.4)
also check if you have any plugins/themes that are conflicting with Yoast.