If you tell the VM to connect to COM1 on the host, but that port is already in use by another host application (e.g., a real terminal program, a PLC programming tool, or another VM), VMware will not forcibly steal the port. Instead, it starts the VM with that device disconnected and logs this warning.
To understand the fix, you must understand the hardware. virtual device serial0 will start disconnected
Manually edit the .vmx file to point to the correct host port by changing the serial0.fileName to the specific port name, such as COM3 on Windows or /dev/tty.USA19H3d2P1.1 on Mac. If you tell the VM to connect to
Open the .vmx file with a text editor (like Notepad or TextEdit). Search for and these lines: serial0.present = "TRUE" serial0.fileType = "thinprint" serial0.fileName = "thinprint" Save the file and start your VM. Why is this happening? Manually edit the