Dear @Bradmu
How many did you try?
There are some ways to try:
1.When upgrading again, please power down and re-start.
2.Unload firewall and reboot PC
3.In stage of upgrade, please close other serial port too or the service that accessed to the serial port
4.The Chinese character, space or bracket are not allowed in tool or firmware path. It will be better to place in the local disc D, E or F.
5.The utilized USB cable and the external power supply to the UBS and HUB shall be industrial.