Today I was struggling with an ESX host. The ESX host was unable to leave the Windows domain. I got the following error:
From the vSphere client I was unable to fix this issue. Apply Host profile failed also with the same error. So I started a search in the VMware KB and found an article about problems while attempting to join a Windows domain. In this article you’ll find a way to clean up the AD configuration from the CLI.
The solution for me was to stop the lsassd service:
/etc/init.d/lsassd stop
Remove the db directory:
/etc/likewise/db directory
and start the lasassd service again:
/etc/init.d/lsassd start
Now I was able to leave the Windows domain.
ICT-Freak.nl 
If you connect vsphere client directly to the ip of the host with the vsphere client, you can usually remove it from AD. You will get this error if you are trying to remove it in version 5.0 while logged into a vsphere client connected to vcenter using an AD account.
I have the same issue, I tried restarting the management services on the host. After disconnecting the ESXi host from vCenter and reconnect the host I was able to power on virtual machines, also my CPU/Memory activity is back