When you try and create a user in the Chatkit instance inspector / console you may see the message An error occurred!
There are two common reasons for this:
1) You haven't added a unique user id in the user creation box
2) The time on your computer is wrong. If the time is wrong by more than 60 seconds the authentication token you receive from the server will be too far out of sync and cause an authentication error. You can check the accuracy of your system time here: https://time.is/