It happens to every blogger sooner or later: The dreaded missing sidebar.

More often than not, the sidebar hasn’t actually disappeared entirely; it’s just at the bottom of your blog, beneath all the posts. Which, of course, is just as bad. We call this a “blown out” sidebar.

So why does this happen? It’s usually due to a handful of common problems:

• Ultra-wide images in posts. That is, images that are wider than the width of the main content area. The main content area on our blogs (where the blog posts appear) is aprox 550px wide. However, there is usually spacing around images, as well as spacing around the edge of the post area. Which is to say, don’t ever make your images wider than 500 px. Put another way: Don’t ever let you images go wider than the right-most button in the editing screen.
• A really, really long URL. This happens if you actually paste the full URL into the text of a post (a no-no). If you’re ever inserting a link into a post, create a hyperlink by highlighting some text, clicking on the link icon (the little button with the piece of chain-link) and then pasting the URL. Putting an actual URL into a post is bad blog form.
• Bad HTML. Text that’s been pasted from MS Word or another site that has < div > or < span > tags. This one is a little trickier to troubleshoot, as text that’s been pasted with HTML formatting is usually riddled with such tags. The easiest method for fixing: delete all the text and follow the instructions for “Cutting and Pasting from MS Word” that I posted on this blog. This can also sometime happen when you’ve got something like a “Read More” tag within a paragraph. It’s better to add a couple of line breaks, and then put the “Read More” line inbetween them. That way the “Read More” line doesn’t run the risk of blowing out the sidebar.
• Ultra-wide sidebar widgets. This is sort of like the mirror problem of images that are too big. The sidebar area is 300px wide, but you really don’t want to put anything in there that goes beyond 275px. For example, if you put in an external widget that’s 350px wide, that will cause your sidebar to get blown out.

So, to sum up, if you have an image that’s 600px wide, your sidebar will get blown out. If you paste a really long URL, it’ll get blown out. If you cut and paste from Word, you’re running a good risk that it may get blown out. And if you put anything in your sidebar wider than 275px, it’ll probably get blown out.

Remember, keep all embeds and images to 500px wide in your posts; 275px wide in your sidebar.