Error communicating with device Errno 22

When attempting to send files to my new Kindle Paper White Signature Edition 11th Generation, I receive the following error:

calibre, version 6.9.0
ERROR: Error: Error communicating with device

[Errno 22] Invalid argument: '/Volumes/Kindle/documents'

Traceback (most recent call last):
File "calibre/gui2/device.py", line 88, in run
File "calibre/gui2/device.py", line 620, in _upload_books
File "calibre/devices/usbms/driver.py", line 331, in upload_books
File "calibre/devices/usbms/device.py", line 901, in create_upload_path
File "os.py", line 215, in makedirs
File "os.py", line 225, in makedirs
OSError: [Errno 22] Invalid argument: '/Volumes/Kindle/documents'