Can't edit the text blocks in my site's Gallery pages

I'm using the Henson template on version 7.0 and recently logged in to edit some pages and create a new one on my site. However, I can't seem to duplicate existing pages OR edit the ones I have (ex: https://www.craigmurray.work/lonely-planet-video).

Why can't I edit the text blocks on these existing pages? Is this page style no longer supported or something?