VCS is for video endpoints outside of your network (such a video conference system) + jabber enabled devices. They are the same product (expressway and VCS)... just with a VCS key you unlock more features.
you CAN still do jabber video with an expressway key. If you need video conference ability from outside your network than you wanna go with a VCS key.
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.