If you’ve recently powered on a VMware Virtual Machine (VM) only to be greeted by the message you aren’t alone. While this warning might seem alarming, it’s usually a minor configuration mismatch rather than a sign of a failing system.

Here is a deep dive into why this happens and how you can fix it. Why Does This Message Appear?

You moved the VM from a host that had a physical COM port to one that doesn't.

Troubleshooting VMware: "Virtual device serial0 will start disconnected"