If you are seeing an error from the codec "The HTTP Feedback for slot X cannot be delivered", there are a few steps you can take to resolve the issue.
First, make sure you are using the latest version of the Vyopta Collector. You can get the latest collector update from the Vyopta Admin Portal
In the newer versions of the Vyopta Collector, we have recently supported HTTPS feedback from the codecs, so your endpoints should be registering via HTTPS, and not HTTP as shown in the screenshot below:
If you see HTTP Feedback using http, and pointing back to the Vyopta Collector, you should unregister the link. For example, if the error was coming from Slot 2, you would use the following xcommand on your endpoint:
xcommand HttpFeedback**Deregister FeedbackSlot**: 2
At this point, a reboot may be required, but you can find more information on this process in our Knowledge Base.