nice nano v2 upload problem

[goktugh]

i am using nice nano v2, burn bootloader works perfect but when I try to upload a sketch, I get this error

Failed to upgrade target. Error is: ClearCommError failed (PermissionError(13, 'The device does not recognize the command.', None, 22))
Traceback (most recent call last):
File "main.py", line 296, in serial
File "dfu\dfu.py", line 235, in dfu_send_images
File "dfu\dfu.py", line 203, in _dfu_send_image
File "dfu\dfu_transport_serial.py", line 155, in send_init_packet
File "dfu\dfu_transport_serial.py", line 243, in send_packet
File "dfu\dfu_transport_serial.py", line 264, in get_ack_nr
File "serial\serialwin32.py", line 275, in read
serial.serialutil.SerialException: ClearCommError failed (PermissionError(13, 'The device does not recognize the command.', None, 22))

Possible causes:

• Selected Bootloader version does not match the one on Bluefruit device.
  Please upgrade the Bootloader or select correct version in Tools->Bootloader.
• Baud rate must be 115200, Flow control must be off.
• Target is not in DFU mode. Ground DFU pin and RESET and release both to enter DFU mode.

[hathach]

which PC OS you are using, look like you have com permission issue. If it is macos/windows, try to run with root/admin right, for linux you need to update udev rules

[goktugh]

which PC OS you are using, look like you have com permission issue. If it is macos/windows, try to run with root/admin right, for linux you need to update udev rules

I am using Windows and have started Arduino with admin permissions. Still, no luck. Also burn bootloader works perfect