Page NOT FOUND

Hi, I have a couple of questions.
I’ve created the custom post type called discussions and added one post. BUT in order to add it to the menu, I have to manually add the discussion post to the menu system. I’ve added it as a sub menu. The actual post type “discussions” does not create a top level menu, and any new post will have to be added manually, which will defeat the purpose of a secondary blog.

However, even when I do add the discussion post to the menu, WP cannot see or find the post page: http://www.wimberleychristianchurch.com/discussions/sept-discussion-notes/

The pages are not found. I tried another custom post plugin with the same result.

https://wordpress.org/plugins/custom-post-type-maker/