Hello Steve,

The "Related Posts" are associated by tags. In other words, those tags that are used in the post determines which posts are related to it. Looking at the tags you have there, all those tags only has 1 blog post and it's the same blog post that you are viewing, hence it isn't showing any related posts. If you add another post with the tag "korea", you'll see it appear on the related posts.

As for the blog categories module not displaying any categories, it is actually because the option "Hide empty categories" is enabled and the parent category is actually empty and that is why it is not displaying them. I have disabled this option and they show up correctly now