[Errno 13] Access denied (insufficient permissions)

[garyfishel]

I have a program running in Windows that utilizes the libusb-1.0.dll backend. The program previously worked consistently without any issues, but after multiple Windows updates in the past few weeks, attempting to set configurations occasionally (but not every time) results in the following error:

Traceback (most recent call last):
  File "D:\real_digital\WebUSB_Adaptation\scope_interface.py", line 48, in connect_to_scope
    cfg.set()
  File "C:\Python311\Lib\site-packages\usb\core.py", line 641, in set
    self.device.set_configuration(self.bConfigurationValue)
  File "C:\Python311\Lib\site-packages\usb\core.py", line 915, in set_configuration
    self._ctx.managed_set_configuration(self, configuration)
  File "C:\Python311\Lib\site-packages\usb\core.py", line 113, in wrapper
    return f(self, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\usb\core.py", line 158, in managed_set_configuration
    self.managed_open()
  File "C:\Python311\Lib\site-packages\usb\core.py", line 113, in wrapper
    return f(self, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\usb\core.py", line 131, in managed_open
    self.handle = self.backend.open_device(self.dev)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\usb\backend\libusb1.py", line 804, in open_device
    return _DeviceHandle(dev)
           ^^^^^^^^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\usb\backend\libusb1.py", line 652, in __init__
    _check(_lib.libusb_open(self.devid, byref(self.handle)))
  File "C:\Python311\Lib\site-packages\usb\backend\libusb1.py", line 604, in _check
    raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 13] Access denied (insufficient permissions)

Any help resolving this issue would be appreciated.

[mcuee]

Make sure you are using a supported driver, WinUSB is prefereed.

[garyfishel]

I am using the WinUSB driver. Switching to the libusb-win32 driver sometimes resolves the issue, but not consistently.

[mcuee]

This does not seem to be a pyusb issue. If you have further issues, ask in libusb project.