Possible ecommerce plugin python bug leading to error 500

This guide suggests that in order to get certificates set up I need to set a course mode:

Also I further set a default course mode of Honor per this:

from django.conf import settings
print(settings.PAID_COURSE_REGISTRATION_CURRENCY)
[‘usd’, ‘$’]
print(settings.COURSE_MODE_DEFAULTS[‘currency’])
eur

So yeah, that seems to be a problem. Is the “PAID_COURSE_REGISTRATION_CURRENCY” possibly left over even after I disabled the ecommerce plugin or is it a side effect of setting a course mode? How can I change that?