I have a MBP 13 mid 2010 with 8 GB Ram, and everything up to date. Yesterday I installed Sierra and everything seems to be working as it should. That said, when I opened Word08mac it came up and then under the widow appeared a white or black box that covered about ¾ of the desktop. It has no effect on the window; they open on top of it. But when the windows are closed, the box is still there. Clicking on it does nothing. So, I quit Word and the box went away. Any idea what's going on? Never saw this until today.