Depending on how much time you are willing to spend now that you have a composite column "solution" ...
It looks like parsing the template passed by the kobo driver is failing, perhaps because of line endings or character set issues. One possible solution is to simplify that template. You can do that by making the original template into a "stored template" then calling that template from one in the kobo driver.
Steps:
1) Make a stored template (preferences / Stored templates) containing
Code:
program:
if field('#readorder') then
template('Reading List: {#readorder} #{#readorder_index:0>2s}')
else
if field('#fanficcat') then
template('{#fanficcat}')
fi
fi
Name it whatever you want, for example subtitle.
2) Change the template in the driver to
Code:
program: subtitle()