Excuse me if this has been addressed. Searched the forums and didn't find a relevant post.
I've been designing websites for decades and I'm now going blind. One aspect in the design window I find very difficult to use is the very narrow and blended color vertical scroller. On the fly, it is very difficult to find as the light grey color is too similar to the medium grey border. It can also be very difficult to get the mouse pointer on it as it is so narrow.
I am designing with Chrome at full screen on a 26" monitor which may also be part of the problem. Designing will make you go blind lol!