No scrollbar in trough

Using Writer v5.2.6.2 on OpenSuSE 42.1. Tried gtk-primary-button-warps-slider = false in the GTK-3 settings file with no difference. The problem is that there is a vertical scroll bar and it works except that you can’t see it in the trough until you hover over it. So, it’s very difficult to determine where in the document I am before scrolling. How can I get it to show up?