The process VMwareService.exe has initiated the power off of computer %computername% on behalf of user NT AUTHORITY\SYSTEM for the following reason: No title for this reason could be found
Reason Code: 0x0
Shutdown Type: power off

1) Check VMware tasks and events for any record of who may have powered off the server. You will probably find no record.
2) Check VMWARE tools are up to date. If not, update
3) Check scheduled tasks
4) Check no one was working that particular day as such power offs are initiated remotely via a different server on the network.