Some 7942 Phones stuck on "Registering" with CME version 8.6
Managed to resolve the issue! It was the end nothing to do with firmware. Apparently there were some Routing/firewall changes made and since the CME is on the other side of the FW from the LAN, the IPS on the FW was dropping some packets after all!.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.