Published pages don’t work

When I try to write a page, I can create it and edit it. It works after I save it, meaning if I click on ‘view page’ I can see it. But as soon as I publish it and try to view it, I get a ‘Page Cannot be Found’ message. This has happened with every new page I’ve tried to create so far. What’s the deal?

I do have my Permalinks set to Custom ‘/%postname%’ Could that be a problem? It works on other WordPress sites of mine, so I don’t know why it would change.