Wy wife booted up her Mac this morning and the dock appears to have lines though it making the icon hard to recognize. I've attached an image of it. A few of the icons seemed to self correct once opened but only a few of them. I'm pretty much at a loss as to what could cause this. She's running 10.12.2 on it and its a late model MacBook Pro, maybe a year or so old. Any help would be appreciated.