missing elements in Firefox display (Linux)

[MaybeYou]

My laptop runs on Windows 10 Home.
I installed the latest Ubuntu as a guest vm in the latest Virtualbox. Essentially that works fine. The mouse and keyboard work well. So does clipboard, etc.
One place where I have some problems is with Firefox. I'll explain.

Using Firefox both in W10 and in Ubuntu, same page, using quick reply in both:

1. the formatting bar is absent in Linux. (Can't upload the screenshot)
On the left in the Ubuntu Firefox (no formatting bar), on the right W10 formatting bar is present

2. scroll bar iis much narrower in Ubuntu than in W10

Can they be fixed?

[DanRaisch]

See this for information on posting a screen shot to the forums http://kb.mozillazine.org/Posting_a_scr ... _the_forum

[MaybeYou]

Here's the screenshot
https://imgur.com/a/35y9igJ