There may come a time when you find that your trusty sidebar has moved from its usual position next to each page and post’s main content, and has instead decided to hang out right underneath.
This is almost always the result of an issue with your theme’s HTML or CSS code. As such, this error is likely due to a recent change to your theme. If you’ve edited any of your theme files lately, try reverting them to their previous states, to see if that resolves the problem.
More specifically, there are two main things you should look out for when troubleshooting this problem:
- Leftover <div> tags: These tags are used to add HTML elements, and if one is not opened or closed properly, it can cause the sidebar to move.
- Incorrect margins in CSS: If the margins are not set correctly in your style.css file, the sidebar may not have the space it needs beside your main content.
Examine your theme for these issues, and you should be able to find the source of the problem. You can also run the affected page through the W3C Markup Validation Service, to help you find the source of the error faster.