[HELP] How do i remove this image??

I updated my theme and i suddenly got this image on top of my every blog.

Hello there,

I hope you are doing well today.

It appears that you do not have a featured image assigned to the posts being displayed so I would recommend that you edit the posts and add a featured image to each of them.

I tried to view your blog but there were no posts available so I was not able to inspect the page.

Here is the link I used:
http://prashunchi.com.np/blog/

Best Regards,
Support