I made a similar post last month and could not figure out why PI was opening to a black GUI. After reinstalling the latest version to give 1.8.6 a try again, I figured out what was causing the issue. My PI was opening in full screen by default for whatever reason. Now I have memorized the keyboard shortcut for fullscreen to counter this issue but I thought I would bring it to your attention.
As you can see in the linked video, when clicking Full Screen, the GUI goes black but I can still see tooltips. If you happen to come around a fix or trick for me to try, it would be much appreciated, as fullscreen mode is useful for my laptop.
https://drive.google.com/open?id=1z8CUYjtU0_dxP6Jj-dC0Z3xqJY_JysvIGraphics driver and computer recently updated.
Windows 7 Home Premium Service Pack 1
GeForce 610M
Intel Core i7-2670QM CPU @ 2.20GHz
8gb RAM
PI version 1.8.6.1457