|
The Kobo devices use a database to record information about the books on the device. This contains the metadata for the books and things like the reading status and shelves. When using the device, the information displayed is from the database. When calibre sees the device, it reads this database to get the information about what books are on the device.
If the database become corrupted, calibre will usually display this error message. You will usually see it when the device is first connected. When it happens, it means a table in the database that is being used by that function is corrupt. During a delete, five or six tables are touch. One of these is corrupt.
Other than calibre connecting to the device, a corrupted database causes other problems. The most common is disappearing books when the device is powered off and on. Or losing the reading status.
Fixing a corrupt database depends on what is wrong. If it is a broken index for a table, these can be fixed by rebuilding the index. I don't know how to fix other problems. If you run the "Check device database" function of the utilities plugin and posting the results, I can see what can be done.
But, as a general rule, if you don't have a recent backup of the database, it is simpler to let the device fix it. To do this, log out on the device. This isn't a factory reset. It doesn't remove the books from the device. It logs you out, clears the database and restarts. Then it asks you to do the setup again. After that, it will load all the sideloaded books into the database and hence the devices library. The log out is on the "Accounts" page of the settings.
|