Which and version you are using (e.g., Workstation 17.5)?
For more detailed guides, you can visit the Broadcom/VMware Knowledge Base or the VMware Fusion community discussions . If you’d like, let me know:
The VM might be configured to connect to a physical serial port (COM1, etc.) on the host that doesn't exist or is currently being used by another application.
If the issue persists after these generic fixes, inspect the .vmx file for configuration errors:
Close any application that might be using the port (e.g., a terminal emulator, legacy software, or another VM). virtual device serial0 will start disconnected
While this warning rarely causes a total system crash or prevents the guest operating system from booting, it adds unnecessary clutter to startup logs and can indicate underlying configuration mismatches. In enterprise environments, resolving these warnings is essential for maintaining clean logs and ensuring that automated monitoring scripts do not trigger false alarms.
Depending on whether you actually need to use a serial port within your virtual guest OS, choose one of the following solutions.
This warning message, , is one of the most common errors seen by users of VMware Workstation, VMware Player, and VMware Fusion.
If you might need the serial port in the future but want to suppress the boot-time error message, you can tell VMware not to connect it automatically. Which and version you are using (e
The resolution depends on your specific needs and configuration:
For debugging, named pipes offer low latency and are ideal for VM‑to‑VM communication. For remote access across physical locations, TCP network connections are appropriate. For logging crash information, file‑based serial ports (stored on a datastore) provide reliable storage.
To completely disable the device, change the lines to match this configuration: serial0.present = "FALSE" Use code with caution.
virtual device serial0 will start disconnected If the issue persists after these generic fixes, inspect the
Emulating unplugged hardware:
One VMware Fusion user reported: "Every time Fusion starts… I get this error message. This is due to Fusion 13.5 removing ThinPrint virtual printing from the product. The message is harmless (although virtual printers are no longer available in the VM)." Solutions range from ignoring it to editing the VM's configuration file to remove ThinPrint‑related lines.
: Sometimes, the virtual machine's configuration file ( .vmx ) may contain outdated or incorrect parameters for the serial port, leading to the warning on startup.