Error communicatine with device

My computer knows that a device is connected but Calibre says "Error communicating with device."

calibre, version 7.12.0
ERROR: Error: Error communicating with device

CorruptError: database disk image is malformed

Traceback (most recent call last):
File "calibre\gui2\device.py", line 111, in run
File "calibre\gui2\device.py", line 565, in _books
File "calibre\devices\kobo\driver.py", line 2032, in books
File "C:\t\t\apsw-42s16m2x\src\cursor.c", line 240, in resetcursor
apsw.CorruptError: CorruptError: database disk image is malformed

Does anyone know how to fix this? In spite of the message, it sends the new version of the Economist to the book reader but also wipes out the database on it. I have to repair the Kobo installation and download all the books again! I have not reset the Kobo which I guess is the next option?