You will see this error if a non-identified client attempts to use a channel whose namespace requires an identified client. The configuration of each namespace is contained within the settings of the application. By default, identified is a namespace which requires identified clients.

Find out exactly what an identified client is.

To change/create/remove a channel rule, go to your application, select the SettingsĀ tab, then go down to the Channel Rules section to setup or modify rules.