Re-open Device Manager, right-click your COM port, select Update Driver -> Browse my computer -> Let me pick from a list , and re-select the original FTDI or CH340 driver from the list.
Maya took a breath and opened the ReadMe.txt . Buried in a wall of broken English was the golden sentence: redsail cutting plotter usb driver install
You should see "Redsail USB Plotter" or "USB Serial Port (COMx)". Re-open Device Manager, right-click your COM port, select
You should now see an entry such as or CH340 (COM4) . Re-open Device Manager