Content in Page edit dissapeared but viewable on website

Hi,

I spent a long time creating some pages in my site and now when I am in the site dashboard and go to pages to edit them, every single page has no content despite each page on the site showing the content I created. All I can see in the page edit is the title, the permalink and then a bar that says avia layout editor and then the rest is blank.

Please can someone advise on what has gone wrong and what I can do to restore the content in the page editor.

Thanks.