The form was working fine before, but now when I submit, it returns to the same page with the fields cleared, and no post created.
We didn't add any new plugins, and I can't find any setting changes that would have affected usp. In my network I've created a new blog with a basic theme and default usp settings, same problem.
Can you suggest a method to check where USP gets stuck? (wp debug didn't show any USP issues)
I have to get it working again! It's an internal staff service, but here's a temporary blog to test http://blogs.mazars.com/sandbox/sample-page