Showing Blank Images

I have been using newspaper x theme for my website But some blank images are displaying in my website.Why that blank images are displaying i don’t know. I am adding Screen shots. Please see Once. Please help me.

Hello there,

I hope you are doing well today.

Please ensure that your posts and pages have a featured imaged assigned to them. The featured image is being displayed but the theme does not have a featured image assigned to the post.

Best Regards,