Mainly, you need to make sure it's:
* A publicly accessible URL (you don't need to be registered to see it)
* It doesn't redirect to another URL
* The URL is 'full', including
yoursite.com/ (ex.
yoursite.com/privacy)
Hope that helps, but if you're still having issues, please let us know the URL you're trying to use as your privacy policy and we can take a look.
Thanks,
Alex