Originally Posted by davidfor
To go back, you can try using the manual firmware method. This should work OK for recent firmware but I'm not sure about the 1.9.x versions or even 2.0.0. These might need a factory reset. If you do that, use the desktop app to do the sync/upgrade to the device but before disconnecting replace the updated firmware files with those for the firmware you want.
Yes you can go back to 1.9.17. A factory reset is definately recommended
before sideloading the firmware although you can
go back without doing a reset. I've done it myself but I don't recommend it, your Kobo will
develope quirks and the firmware already has enough of those.