Featured Image not Showing

Hi,

I am having problems with images displaying on my website. I create a page, choose a featured image for the page, save all the changes etc but the pic doesn’t show on the re-loaded webpages.

When I create a new post, the same things happen, I can see all the text but no picture.

Is this an issue with my theme? Or is there a setting I should look at?

Any help would be app’d.