Serial communication with pySerial on windows

Hi. I’m trying to communicate with robocore board through USB cable with python. I read in this forum that i have to uninstall WinUSB driver from zadig and instal USB serial one. I am using this code:

import serial
port = ‘COM6’

ser = serial.Serial(port, baudrate=9600)

And get this exception:
Traceback (most recent call last):

'Original message: {!r}'.format(ctypes.WinError()))

serial.serialutil.SerialException: Cannot configure port, something went wrong. Original message: PermissionError(13, ‘A device attached to the system is not functioning.’, None, 31)