Calibre sees my Kindle but doesn't allow books

calibre, version 2.85.0
ERROR: Error: Error communicating with device

Failed to access files in the main memory of your device. You should contact the device manufacturer for support. Common fixes are: try a different USB cable/USB port on your computer. If you device has a "Reset to factory defaults" type of setting somewhere, use it. Underlying error: [Errno 1] Operation not permitted: '/Volumes/Kindle/driveinfo.calibre'

Traceback (most recent call last):
  File "site-packages/calibre/gui2/device.py", line 88, in run
  File "site-packages/calibre/gui2/device.py", line 471, in _get_device_information
  File "site-packages/calibre/devices/usbms/driver.py", line 153, in get_device_information
IOError: Failed to access files in the main memory of your device. You should contact the device manufacturer for support. Common fixes are: try a different USB cable/USB port on your computer. If you device has a "Reset to factory defaults" type of setting somewhere, use it. Underlying error: [Errno 1] Operation not permitted: '/Volumes/Kindle/driveinfo.calibre'

i've used calibre for years but now doesn't have "send to device" . Above is the error message. Please help. I have tried and been unsuccessful.