"Create New" Doesn't seem to work…

When I select Create New to create a new page, I get taken to


So I put the title and text in (“Test 1” in both), click Save, and then I get taken to


Which says that the page does not exist, and would I like to create it?

It has also then lost all of the text for the new page, which is really frustrating!

Am I missing something?

Anybody is welcome to register on the site to try it out if you want.