Edit Page Blank???

Hello everyone,

This is pretty strange to me. I am working on a client’s website, editing their SEO with the YOAST seo plugin, adding some images and what not. All of a sudden on the next page that I go to edit, I get this blank page. The edit page opens with the black dashboard admin border with all the options: Pages, Appearance, Tools, Settings… and so on. But the HTML/TEXT box is not there or the categories, tags, featured image, excerpt. Nothing is there. I clicked on Screen Options but it does nothing.

This happened when I updated a page and when the Edit Page refreshed it started showing me the blank page.

Any ideas on how to fix this? Literally 2 minutes ago it was working fine and now this is happening on every page and blog post.