If you need to use 50 users in the group then you don't need license for Informacast solution .If you are looking for advanced features as well more than 50 users you need to have License for informacast . http://www.cisco.com/c/en/us/support/docs/unified-communications/paging-server/117059-configure-informacast-00.html
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.