If access is via the network instead of the Chameleon software and you receive the message "Error 403 Forbidden", that means that the networked receivers are already being controlled by another client device in the network. Access is limited to one client device for controlling and monitoring.
However, if there is no other client device active in the network and you receive the message anyway, you should reload the page or refresh it. In most browsers, you can do this by pressing the F5 key or by clicking on the "Refresh icon" next to the address bar. If this does not give you direct access, wait around 10 seconds and try again.