Do you have the correct common phone profile set on the phone that contains the VPN gateway and VPN profile? Having that configured on the phone will put the VPN information into the phone's TFTP configuration file so that the VPN button displays on the phone. If you have the common phone profile set already, make sure the phone is accepting its configuration file by looking into the status messages for any error messages.
The phone will not display the VPN button until the VPN gateway and profile are configured in CUCM and then set on a common phone profile, and then the common phone profile set on the phone itself. The phone then has to be reset so the phone downloads its TFTP configuration file with these new settings. Once all of this has happened the phone will then display the VPN button.
Yes the VPN information is written into the TFTP configuration file.
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.