https://bugzilla.wikimedia.org/show_bug.cgi?id=72047
--- Comment #13 from Fabian CommodoreFabianus@gmx.de --- Okay maybe the families are not loaded properly? Have you changed the "installed" families? With the following code line (in the shell like before) it'll list all families:
print("\n".join("{}: {}".format(*i) for i in sorted(pywikibot.config2.family_files.items())))
The default installation should contain at least outreach, wikidata and commons.