What versions of CUPC, CUPS, CUCM and MP are in use? I'm not sure if it's supported but if you collect a set of detailed CUCM traces and provide the calling and called party numbers I can go through and verify the reason for the disconnect.
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.