Background
I have Xenial Xerus installed on a Mid-2014 Macbook Pro OSX High Sierra host, running in a VMWare Fusion 10 instance.
On Fusion 7, I had no issues with Ubuntu on VMWare. However, since I also virtualize my Bootcamp partition for convenience... I was forced to update to 10 since 7 no longer supports loading Bootcamp on the latest OSX.
VM specs
3 Cores, 4GB ram, 20GB HDD (10GB free), Hardware version 14. 768MB VRam
Issue
I just cannot ever restart or shut down the VM. If I restart or shut down Ubuntu, on the next reboot, I get the message: "Sata device 0:1 could not be connected, always try to connect when starting this VM?". Then, Ubuntu starts in low graphics mode, and I am forced to restore a snapshot of my VM when it was working. This is workable, with proper snapshotting and backing up I have been passably using Ubuntu. However, I have had to go into the console in low graphics mode after a crash and back up my work, restore snapshot, and restore my work many, many times. Conceivably if I ever start leaking memory and need to reboot, I'll need to re-image the VM again.
What I've Tried
Different allocations of ram, cores.
Reinstalling x-desktop
Reinstalling/updating Nvidia drivers (this broke the hell out of the VM when I tried)
Reinstalling VMWare tools
Reinstalling Ubuntu.
Installing all manner of different desktop environments