Newbie cannot connect Paperwhite to Calibre

Hello all,
I am a newbie to the forum and hope that you may be able to help me...

I have been using Calibre and Kindle Paperwhites for years with no problem.
Now I get the following error on all computers and Paperwhites:

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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 13] Permission denied: 'V:\\driveinfo.calibre'

Traceback (most recent call last):
File "site-packages\calibre\gui2\device.py", line 89, in run
File "site-packages\calibre\gui2\device.py", line 472, in _get_device_information
File "site-packages\calibre\devices\usbms\driver.py", line 160, 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 13] Permission denied: 'V:\\driveinfo.calibre'

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I have reset four paperwhites, changed several USB Cables, and updated Calibre on several Windows 7 and Windows 10 computers. The Kindle is visible and accessable as a drive in Windows.
All Paperwhites work normally and wireless is fine.
I just can't connect the Paperwhite to Calibre in order to transfer books from my libraries to the Kindle.
Any ideas? Help!