I encountered this error locally and also by using docker-compose on GCP.
The error in browser console says: Objects are not valid as a React child (found: object with keys {type, payload}). If you meant to render a collection of children, use an array instead.
Some socketio conversations are showing at the beginning, but most of them fail after a number of user messages and just show this error.
NLU data from these conversations is properly loading in NLU inbox.
I am using Rasa x version 0.37.1. This also happened with version 0.37.0.