In VMware Workstation, when you edit VM settings, you can choose:
If you don't need to print from the VM, the Printer device.
Most modern virtual machines (Windows 10/11, Linux servers, Ubuntu) do not require a physical serial port. Removing it is the best way to get rid of the warning. your virtual machine. Open the VM settings in VMware Workstation/Player. Select Serial Port 1 (or Serial0 ). Click Remove . Click OK and start the virtual machine. Solution 2: Disable "Connect at Power On"
To remove: Select the serial port and click . virtual device serial0 will start disconnected
, a technology that allows a virtual machine to use the host's printers. When VMware can't find the necessary driver on the host or the feature is turned off in the main preferences, it alerts you that the device won't be active during the session [ Are you currently using a
If you wish to keep the device but stop the error, expand the serial port options and uncheck .
Note: Always take a backup copy of your .vmx file before editing it manually. Power off the virtual machine. In VMware Workstation, when you edit VM settings,
Understanding and Fixing "Virtual Device Serial0 Will Start Disconnected" in VMware
| Step | Action | Detailed Explanation | | :--- | :--- | :--- | | | Check Virtual Printer | In VMware, go to VM > Settings and remove the virtual printer or disable "Connect at power on". This directly addresses the most common cause. | | 2 | Inspect Host COM Port | If using a physical serial port, verify it exists in Device Manager (Windows) or as /dev/ttyS0 (Linux) and is not in use by another program. | | 3 | Verify VM Serial Port Path | In VM settings, ensure the path to the serial device is correct. Change from "Auto" to a specific path like /dev/ttyS0 . | | 4 | Check GNS3 Hardware | For GNS3 users: Verify the correct WIC (e.g., WIC-2T) is installed in the router's slot before powering on. | | 5 | Review Network Cabling | For GNS3 users: Ensure one end of the link is a "Serial DCE" cable and, if needed, the DCE side has a clock rate set. | | 6 | Explore Power Management | Rarely, host power management can interfere. In Device Manager, disable power saving for USB Root Hubs and the COM port if present. |
Locate the virtual machine, right-click it, and select . Look through the hardware list for Serial port 1 . your virtual machine
Locate and open the .vmx file using a text editor like vi or Notepad++. Search for lines beginning with serial0 .
Full log example: