While Yosemite recognise both screens, the parallels is not. Windows 10 new clean installation, mac pro retina 2015, parallels 11 pro. I am working with DVI, used to work with parallels 10. Plugin it out and inserting is not working, restarting vm is not working also. Thanks, Ady.
Make sure you have at least one additional desktop created on the second display in Yosemite so that you get the option to open on a desktop on second display is available in the contextual dropdown Options in Finder or the Dock.