Glitchy scrollbar obscuring content

I'm having this issue where the scrollbar in some apps has this big white box obscuring text. I've only encountered this bug on my install of ubuntu MATE. My other install is plain ubuntu with MATE installed later and it doesn't have this issue.

Note that the box at the top/bottom seems to come from the vertical scrollbar, and the one at the top dissappears when you scroll all the way up.

I'm not sure whether this is the right place to ask but I've only encountered this bug with ubuntu MATE and google doesn't give any relevant results.

Can't reproduce on 16.04 using custom appearance settings: colors from Dark MATE + Borders & Icons from Ambiant MATE.
I'm also seeing on your screenshot that the window lacks its border.

Edit: oh, never mind that last thing, I didn't noticed your image was cutting at the right corner, you do indeed have the border.

Edit 2: I'm running 16.04 LTS 64 Bits with MATE 1.12.1 on a processor with Intel integrated graphics (i915)

Is this only the updater or are other programs also doing it? Sometimes an easy fix is just to change themes.

Changing themes seems to help indeed, can’t believe I didn’t think of that. The offending theme seems to be yuyo (which I believe comes standard with MATE?). Also, the glitch occurs in a lot of seemingly random apps, like eclipse and synaptic, and also a bunch of the settings dialogs resembling the updater.

Then this is solved?