After upgrading my vCenter 6.7 to vCenter 7 (lot of vCenter plugin/extension unregister https://tinyurl.com/y9lwxszh ) I noticed the following items
- vCeter reboot was super quick!
- Guest OS incorrect error message
- Shutdown the vCenter
- Upgrade the VM hardware version
- Edit settings > VM Options > General Options > Select VMware Photon OS
- I had to restart the services number of times via VAMI or SSH
- vCenter 7 is CPU and memory hungry! so I had to throw few more vCPUs and vMemory to my nested vCenter!