I’ve not heard of that kind of an issue before. To help I’d need a better idea of what you’re seeing. I assuming readers are trying to comment on a page that you’ve made private with WPSentry. What theme are you using? What version of WordPress? If you’d like to add a link to your site I can try to take a look.
This is what the first user sees when they try to comment: http://grab.geekpowered.me/NHGy
This is the test post I created: http://geekpowered.me/2016/01/28/test/
In the prior post, I turned off WP Sentry and it allowed people to comment. As an admin I can reply to comments with WP Sentry turned on, however, non-Admin users get the routed to the page showing in the screenshot.
In addition, as an Admin if I try to comment on a post that has no comments, it takes me to the Oops, page not found page, but as a Subscriber, it takes me to a blank page.
WordPress is up to date: 4.4.1 and I am using a custom theme.
Thanks. When I try to go to your test post, it gives me not found as well. Based on your description though, I’ll try to duplicate it here and see what I find.
I had nothing specified in preview link in the preview settings so it should have disabled it, however I have since changed it so now when you click it should take you to a friends only page.
Hello do you fix this? I have the same problem.