If you’re reading this, you probably know what I’m talking about.
When you have bookmarks in sub folders, you can choose to open all of them with one click. This is a great feature and I use it all the time. For instance, most mornings I open 10 news bookmarks with one click. Really, it’s quite the timesaver.

The problem is that these new tabs replace the previously opened ones. I always thought I was being stupid and couldn’t find the right box to checkmark in the options. Nope, me no stupid, there is no option.

There is however a hack:

1. First off, in the address bar type - about:config (then enter)
2. Next: copy this line into the Filter bar: browser.tabs.loadFolderAndReplace
3. Finally: Double click the line and make sure it ends up FALSE

That should do the trick.