I received this response from a local SE in Australia.
8831 phone Issue : Wireless microphone region
Please be advised that the Cisco 8831 conference phone must be set to the Localised Wireless Microphone Region. If it is left to Default (aka US if no Locale is set) it will use the 1900MHz frequency for DECT, hence affecting mobile frequency networks and in breach of the Communication Frequency Regulation laws.
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.