I assume you were using an add-on for this since as far as I know, it's not a built-in option.

You could check out other add-ons if the old one has stopped working. For example:

https://addons.mozilla.org/firefox/addon/roomy-bookmarks-toolbar/

That's the only one I remember off the top of my head, I don't use it myself.

In fact, I cannot find any options to customize the bookmarks toolbar in any way, apart from +/- and rearranging bookmarks. Where have the other options gone?

Sorry, what were the other options?? Firefox 29 and newer don't have a lot of built-in toolbar customization options.

If you check your Add-ons page, can you see any bookmark-related extensions there. Either:

• Command+Shift+a (Windows: Ctrl+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then skim down the right side. If an extension is disabled, it will be at the bottom on a grayed background. If it's just not working, it could be anywhere.

To try to update extensions, you can use the button above the list that has a "gear" (or wheel or cog) icon, click that, then Check for Updates.

Thanks very much for reccing the Roomy Bookmarks addon; I'll try it tomorrow. Glad there are some solutions available.

I'm just frustrated because I didn't have any bookmark-related addons, nor did I lose any with the latest update, which is why I assumed it was a Firefox-native issue. I'm glad there's a workaround, but it's troubling not knowing where a problem came from. I don't have that many addons to keep track of in the first place.

Thanks again for your help!