If you haven't done so,take time after you fix things and set kobo utilities to back up the DB. I bumped the default copies to 10 as I frequently connect. YMMV a device (restore is a manual file copy+rename)
As you can see, it also supports multiple Kobo's, even if they are not the same model (No, don't think of using a db from a different serial. I have no clue how bad things will get
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