If you followed davidfor's instructions, which files *exactly* did you replace before restarting?
1. Factory reset your device
2. Plug your device into your computer
3. Do the setup, let it download the new firmware
4. Do NOT unplug
5. Browse to [YourKobo]/.kobo folder
6. Remove three items:
6.3 upgrade (folder)
7. Unzip your 1.9.14 firmware into the same .kobo folder. You will get three items with identical names to the ones you just deleted
8. Eject your device, and unplug
The update should proceed automatically.