This document contains a list of common problems that you may run into while working with this library.
If you are using express-stormpath as your back-end you may see this error when attempting a social login. This happens if the Body Parser module is configured before the Express Stormpath module. If you must do this, please ensure that you are enabling the extended option for the parser:
app.use(bodyParser.urlencoded({ extended: true }));
This issue is being tracked here: