Are you trying to power on a virtual machine on your ESXi host and VMware Workstation is telling you, “Unable to change virtual machine power state: Module ‘MonitorLoop’ power on failed.”
There are two reasons you’d be seeing this.
- Your datastore is running out of disk space
- You recently experienced a power outage and forgot to turn your NAS datastore back on. Turn it on.
Hat-tip to Duncan Epping at yellow-bricks.com.