On Firefox, my favorite add-on is Tree Style Tabs (download), because

1. you can see all of your tabs and their names
2. tabs have hierarchy (parent > children > grandchildren)

Once you use it, you will always want to use it, especially at work. But if you get the error message “failed to get permissions to create bookmarks“, you need to grant permissions to the add-on. This is not straightforward. The notification will probably be cutting off some of the words! But if you got here, this is how you do it.

Go to Add-ons > Extensions > Tree Style Tabs > more.

You should see this, so check the checkbox next to “Allow to create bookmarks”

You might get another error message! This is because this add-on’s preferences page cannot request access to the bookmarks. So, you now need to click on the add-on’s icon in your toolbar:

And follow the prompts there. The confirmation dialog will likely appear on the top left of your browser window!