Admin Users Page (users.php) not found

A client just changed to a Dedicated IP. Now I can’t access the ALL USERS page in the Admin Dashboard (wp-admin/users.php). I get a Page Not Found error.

I can access all other Admin pages I’ve tried so far from the Dashboard, including Add New User and User Profile. And yes, the page /wp-admin/users.php is on the server.

I had a problem after the new IP propagation with some permalinks not working. They worked if I switched to Default, but not to PostName. Some worked, others didn’t. .htaccess was fine. I finally went in and changed each of the offending page URLs in Admin and voila, that fixed it.

I’m mentioning that in case it has any bearing on the subject.

Any ideas?

Thanks