Error : Resource busy

[vinaybysani]

Got the following error.
Any Idea?

python server.py
ERROR:cflib.crazyflie:Couldn't load link driver: [Errno 16] Resource busy

Traceback (most recent call last):
File "/home/arcl/git/crazyflie-lib-python/cflib/crazyflie/init.py", line 218, in open_link
link_uri, self._link_quality_cb, self._link_error_cb)
File "/home/arcl/git/crazyflie-lib-python/cflib/crtp/init.py", line 91, in get_link_driver
instance.connect(uri, link_quality_callback, link_error_callback)
File "/home/arcl/git/crazyflie-lib-python/cflib/crtp/radiodriver.py", line 188, in connect
address)
File "/home/arcl/git/crazyflie-lib-python/cflib/crtp/radiodriver.py", line 98, in init
_RadioManager._radios[self._devid] = _SharedRadio(self._devid)
File "/home/arcl/git/crazyflie-lib-python/cflib/crtp/radiodriver.py", line 67, in init
self.radio = Crazyradio(devid=devid)
File "/home/arcl/git/crazyflie-lib-python/cflib/drivers/crazyradio.py", line 126, in init
self.dev.set_configuration(1)
File "/home/arcl/.local/lib/python2.7/site-packages/usb/core.py", line 869, in set_configuration
self._ctx.managed_set_configuration(self, configuration)
File "/home/arcl/.local/lib/python2.7/site-packages/usb/core.py", line 102, in wrapper
return f(self, *args, **kwargs)
File "/home/arcl/.local/lib/python2.7/site-packages/usb/core.py", line 148, in managed_set_configuration
self.backend.set_configuration(self.handle, cfg.bConfigurationValue)
File "/home/arcl/.local/lib/python2.7/site-packages/usb/backend/libusb1.py", line 794, in set_configuration
_check(self.lib.libusb_set_configuration(dev_handle.handle, config_value))
File "/home/arcl/.local/lib/python2.7/site-packages/usb/backend/libusb1.py", line 595, in _check
raise USBError(_strerror(ret), ret, _libusb_errno[ret])
USBError: [Errno 16] Resource busy