Unable to query Region detail endpoint

[CloudNiner]

Made a request like so:

http GET https://app.climate.azavea.com/api/region/18/ format=json 'Authorization:Token <token>'

Requests to the Region list endpoint are fine.

Rollbar error:

[ClimateChange] production - New Error: AssertionError: ("Creating a ModelSerializer without either the 'fields' attribute or the 'exclude' attribute has been deprecated since 3.3.0, and is now disallowed. Add an explicit fields = 'all' to the RegionDetailSerializer serializer.",) https://rollbar.com/Azavea/ClimateChange/items/150/