why less file is not generating changes in min file ?

Hello,

I have Premium version of Visual Studion 2013 and I have installed Web Essentials 2013 . I restarted the VS 2013 2 times even though I am unable to generate changes in min.css file when I modify in main css file.Can you please suggest the reason for the same ?

I also observed that right click of less file > Web Essentials and all the options are disabled as below – what can be the wrong in settting ? 

Please help me out for the above issue as I am unable to find out the root cause.Your help will be highly appreciated.

Thanks and Regards,

Dipti Chhatrapati