Could you be more specific about which toolbar is missing? If you had created your own custom toolbar (not a toolbar created by an add-on), Firefox may have moved all of your icons from that custom toolbar onto the main toolbar, or the overflow list for the main toolbar.

Or if you mean the main navigation toolbar, that should not be hidden. Does the page content take the full screen? If so, could you switch between views, i.e., if you are in full screen view, press the F11 key to switch back to normal view, if you are in a maximized window, try a normal window, etc. Any change?

Before I had a toolbar with functions that you could customize like cut and paste - change font size - forward or backward, stuff like that - it was there before the update but now its gone and I can't get it back. thanks if you can help - your suggestions above don't fix the problem