That suggests that something in the El Captain update has changed how the USB drives are handled. Unfortunately, I don't have a Mac to test with. But, does the Kobo desktop application work with the device? Can you access the database on the device using an SQLite database manager?
That suggests that something in the El Captain update has changed how the USB drives are handled. Unfortunately, I don't have a Mac to test with. But, does the Kobo desktop application work with the device? Can you access the database on the device using an SQLite database manager?