I've also seen this error on out IP Phone. When I use the "&" sign in a user name and search that name in the corporate directory on the 7940/60 Phone The error appeared on the phone screen. Maybe this wil; help you finding your problem ?
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.