When you play around with permalink structure on WordPress, sometimes the content would disappear when you head to a single posting instead of viewing everything on the front page or category page. I faced with this problem when setting up a different site, and kinda felt like a weirdo, since I was the only one reporting this bug, if you search WordPress support site via the_content tag.
The problem is content completely disappearing, with titles and everything else, including templates, appearing on the page with no problem. Apparently it only happens when you want to combine the %post_id% and %postname% tags for the mod_rewrite permalink generation in WordPress options. The solution? What I found to work is replacing the_content() call in the index.php file (or wherever your page content is generated, which could be single.php in some themes) with
<?php echo $post->post_content; ?>
Thanks to unrelated support topic.
