Virtual Device Serial0 Will Start Disconnected -

When powering on a virtual machine (VM) in VMware Workstation, VMware Fusion, or ESXi, you may encounter a pop-up warning stating:

serial0.present = "TRUE" serial0.startConnected = "TRUE" serial0.fileType = "file" serial0.fileName = "/vmfs/volumes/datastore1/vm_folder/serial.log" Use code with caution.

On Windows, right‑click the VMware Workstation icon and select Run as administrator to ensure VMware has the necessary permissions to access the hardware ports. virtual device serial0 will start disconnected

If a physical COM port does exist, another background process on the host operating system—such as an active Arduino IDE connection, serial monitor tool, or custom hardware service—might be monopolizing the port resource. Hypervisors require exclusive access to bind the hardware to a guest environment. How to Fix the Error

A VM configured with a host-dependent serial port connection was migrated to a new host that does not share the same hardware topology or file paths. How to Fix the Error: Step-by-Step Solutions When powering on a virtual machine (VM) in

The error occurs because the virtual machine's configuration file ( .vmx ) instructs VMware to connect a virtual serial port (COM port) to a physical or logical resource that is missing, busy, or inaccessible on your host machine. The most common triggers include:

The warning carries unique implications in different operational contexts. Hypervisors require exclusive access to bind the hardware

The virtual port is mapped to a physical COM port on your host computer (e.g., COM1cap C cap O cap M 1

If you have ever fired up a Cisco router in , GNS3 , EVE-NG , or Cisco Packet Tracer , you have likely seen the console output slowly crawl by until it halts at a seemingly concerning line: