Comment 17 for bug 1523291

That error comes from the sqlite library failing to open the database
file, not calibre code. The issue is most definitely not in calibre
code. Given that the sqlite library is one of the most stable peices of
software around, the issue is almost certainly in device firmware.

Copy the KoboReader.sqlite off the device, and do the following:

Run:

calibre-debug -c "import sqlite3; sqlite3.connect('/path/to/copied/KoboReader.sqlite')"

This is the exact code that is failling in the driver.

You will either

1) get an error, in which case you will not be able to
open the sqlite file with other software either, indicating the file is
corrupted. Presumably the kobo firmware rebuilds/repainrs the file on
disconnect.

2) Or it will open, indicating that the problem is with reading the file
over the USB connection -- which means the device firmware does not
implement the USB Mass storage spec properly.