Comment 2 for bug 1635909

That is a problem cause by the migration of the driver configuration to the new configuration. This error has occurred because your configuration was last changed with a version of calibre that is at least two years old. When I change the configuration code and wrote the migration code, I missed this possibility. I have just updated the migration code to solve this problem. This should be in the next release of calibre.

In the meantime, the workaround is to delete the configuration file and reconfigure the driver. With calibre closed, delete the file "device_drivers_KOBOTOUCHEXTENDED.py" in the calibre configuration directory.