[Kobo Libra] 'Error communicating with device'

I received my new Kobo Libra H2O device today and I've tried to transfer my ebooks after installing the latest calibre and all I get is the following error:

calibre, version 4.2.0
ERROR: Error: Error communicating with device

'NoneType' object has no attribute '__getitem__'

Traceback (most recent call last):
File "site-packages\calibre\gui2\device.py", line 90, in run
File "site-packages\calibre\gui2\device.py", line 594, in _upload_books
File "calibre_plugins.kobotouch_extended.device.driver" , line 399, in upload_books
File "site-packages\calibre\devices\kobo\driver.py", line 2095, in upload_books
File "calibre_plugins.kobotouch_extended.device.driver" , line 313, in _modify_epub
File "site-packages\calibre\startup.py", line 89, in expanduser
TypeError: 'NoneType' object has no attribute '__getitem__'


Can someone please assist with what is causing this and how to fix?

I have had Calibre installed for years with no issues like this with my previous Kobo that died a few months ago and I've been able to transfer the books to the even older Sony ereader.