Virtual Device Serial0 Will Start Disconnected -

If you unchecked "Connect at power on" but still get the message:

When the VM starts, the following informational message is logged: virtual device serial0 will start disconnected

virtual device serial0 will start disconnected

The virtual serial port (serial0) has been configured, but it is not connected to anything (e.g., no pipe, no TCP socket, no physical COM port) at the moment the VM or device starts. The hypervisor/simulator is simply informing you that the port exists but is not active. If you unchecked "Connect at power on" but

For most users: No. The warning is completely harmless. The virtual serial port (serial0) has been configured,

For certain users: Yes, you need to address it.

You should fix this if: