CoolMasterNet requires USB Driver installed for both Application (regular) and Bootloader modes. If for some reason USB driver was not properly installed, it can be fixed/forced with free Zadig tool.
WinUSB Driver for CoolMasterNet will be installed. Now you can use CoolAutomation FW Update Tool. If USB Driver is required for Bootloader mode CoolMasterNet should be in Boot Mode during procedure mentioned above.