Fix mobile usage issues warning

I received a webmaster (Google) warning as of today. According to the warning:

Google systems tested … pages from your site and determined that about 22% of these pages have significant errors related to mobile usage. The errors present on these … pages seriously affect mobile users’ experience of your website. These pages will not be viewed as mobile-friendly by Google Search, and as a result, their rankings will be determined and displayed accordingly in searches by smartphone users.

On April 21, a new update is coming and sites without mobile compatibility will be in trouble. source: http://www.mynet.com/teknoloji/google-arama-sonuclarinda-radikal-degisiklige-gidiyor-1743591-1

Even though my site is mobile compatible, I received this warning. I check on the analysis site. It finds many deficiencies. **My theme: ** http://themeforest.net/item/flavor-responsivehd-magazinereview-ajax-theme/4817769

Do you think I should change the theme?