login_success view is broken

Plone 5.2
pas.plugins.authomatic 1.0b1

I have this plugin configured for github and it works nicely. However, when a user logs in, they are taken to the `login_success` view, which returns a 404 (This page does not seem to exist ...). However, the user is actually logged in at this point.

My only doubt is in the configuration on the github side, where I set the `Authorization callback URL` to http://192.168.20.129:8082/Plone (I'm testing a local development site), same as the `Homepage URL`. Not sure if that should be set to anything else.