macOS Sierra 10.12 ghost window space After installing macOS Sierra 10.12, I have started seeing these ghost windows across the top of the screen. Unfortunately they are appearing at random and I can not determine if this is the OS, a specific application, or a general bug of some kind.  

Has anyone else come across this and a way to fix it without rebooting your Mac? 

Example:

Updates


I have tried restarting finder...
It seems to occur after the screen saver is initiated but I can not confirm...


Plan of Attack


Next time is occurs I am planning on running through all of these commands.
Force quit Finder.app using this method:


Terminal: "killall Finder"


or


hold the Option key and right click on the Finder icon in the dock. Select "Relaunch"