Well, that's embarrassing. I think that has been there since the first release. It would only happen if the config file did not have a "Reading" section in it. So, I suppose it isn't that surprising.
Anyway, I have fixed it with a few other small fixed. The new version is 2.11.4. The changes ae:
- Fix: Updating parsing of firmware update file name to get the version number.
- Change: Display lookup name for columns in Date added choice in Update metadata dialog.
- Change: Add custom date columns and file timestamp option to Date added choices in Update metadata dialog.
- Fix: More fixes for Python 3.
- Fix: Error if setting font in config file if no "Reading" section.
This will be announced by calibre in the next hour or so. If there are any problems, please post the details here.