I had this one, even in Windows 8.1. Now, I have it in Windows 10. However, it only started about a few months ago. Not sure exactly what could have been a factor here. No new version was installed. However, it started to do that just like that. The fact is, once you click on a zip file, it opens the interface showing all the files. Then, there is supposed to be a vertical scrollbar. It does not appear. We have to move the mouse over the scrollbar for about 1.5 seconds, then it appears. This is counter intuitive as far as the user's side is concerned. However, I have the feeling this could be a bug. I wouldn't believe they would have done that intentionally. The reason I mention this is because I have observed something like that recently in IE into which I had to force a CSS declaration so the verticall scrollbar would be visible when there is a need to.