I haven't had that problem but I've just read of somebody with it on Mozilla Connect. They were advised to right-click where the + should be then to choose Customise Toolbar and drag it out. https://connect.mozilla.org/t5/discussions/new-tab-quot-quot-and-toolbar-missing-after-most-recent-update/m-p/73087#M28001

Pillenwerfer!

I do not have Mozilla Connect, but you solved it! Worked beautifully.

How do I get rid of the LIST ALL TABS tab? I tried dragging that into toolbar earlier but it wouldn't drag.

Thank you so very much.

Getting rid of List All Tabs can be done but it's far from as simple as dragging it. See: https://support.mozilla.org/en-US/questions/1466632#answer-1678349

You are correct. May try it later when I have time.

Thank you.

What was the reasoning for moving tabs?

I find it odd and utterly unhelpful. I keep reaching for it but it's not there.

Wish they would change it back as I cannot find the purpose.

Thank you.