That was when I was having problems with my Centralite 4200-C not working right with the C-8. They would lock up and the only thing that would free them up was unplug/replug. At some point during my troubleshooting I hit the firmware update, apparently while the plug was still acting up.
This was when I came to the conclusion that the Centralites didn't play nice with the C-8...or vice versa.
I do own a number of the centralite 4200-c plugs, however I am on a C-7, have never updated the plugs firmware, and the plugs appear to be operating normally. The only firmware updates I perform have been for inovelli blue switches and I have never had a problem with them.
I wish there was a way to tell which device is causing the warnings. @bobbyD
I am still getting these frequently as well. Just saw the link to the other thread, good idea to try and find out what it is, leave Zigbee logging on and see what device matches up with the time of the warning. I must give it a go.