"You are viewing an inexistent page." Inexistent, though it sounds weirder than nonexistent, is still a legitimate word choice. Regardless, though, the illogic of viewing something that doesn't exist, and therefore cannot be viewed, is, well, wonderfully excruciating. I must stop thinking about it...it's making me twitch. The fact that the sentence apparently continues "you can create it by mistake..." is just one of those happy acts of serendipity caused by my lack of (conscious) attention while I was cropping the image.