Noticed a huge chunk of missing posts (screenshot from my homepage). Amit’s stats plugin also confirms that I only have 355 posts as opposed to 2000+ This happened after yesterday’s design changes. I’m using the Ink theme via plugin and have created a custom theme to insert code for Sod’s engagement plugins on the single post template.
I’ve seen this once or twice and I’m trying to track it down… I think it can happen after making subsequent site changes, but hopefully rarely. I expect it should fix itself after the next post or if you click Account → View logs → Rebuild.
Yup, I’ve noticed it after making site changes. But this time, I let it sit overnight but was the same in the morning. I know that the posts are there and just not showing up.
Doing the rebuild now. This is good in a way because it keeps me from tinkering around too much 
I noticed this happening yesterday/today when I made changes to custom CSS, or edited categories. It consistently eliminated about a year of posts!
I’m currently running the tiny theme by @Mtt with a bunch of custom CSS.