Some static map requests fail with Bad geojson - unknown type ExternalData
The error is produced by this code in kartotherian/snapshot.
ExternalData is supposed to be handled earlier by this code in mapdata.
See
https://maps.wikimedia.org/img/osm-intl,3,52,-110,500x500.png?lang=en&domain=www.mediawiki.org&title=Help%3AExtension%3AKartographer&groups=_548ad9e792478e08584ac04c187e4de43a8028cc
from
https://www.mediawiki.org/wiki/Help:Extension:Kartographer