I would suggest using the latest CW v10.5 for your development!
regarding to your problem, it seems to be a driver issue.
could you please uninstall item "LiUSB-Win32 Devices-> OSBDM/OSJTAG-..." and "Ports(COM & LPT) ->OSBDM/OSJTAG-CDC Serial port..." in Device Manager of your Windows system.
and then re-plug your board to let the PC find the driver automatically (usually, it will find several versions driver, please select the latest version).
hope it helps!