I have been using Parallels on my Mac for many years and versions. My computer is MacBook pro I7 with plenty of space and memory. I have Bootcamp, a VM from the Bootcamp, and two other VMS (Ubuntu and Kubunto) I had Win 7 and while using Parallels 10 upgraded to Win 10. No problems but I was aware of the fact that they were not compatible, so I just used the VM. When Parallels 11 came out, I bought it right away. It ruined my Ubuntu VM and my Win 10. Had to restore my Win 7 on the bootcamp, and then create a VM and upgrade to Win 10. It worked before. Now Parallels is slow, choppy, and it freezes again and again. It is the worst version yet, feels like a half backed product. I wish I would have waited. Not sure if I can fix it or just have to wait for an update with hopes that it would be fixed. In the meanwhile my VMs are not usable...