I wish it was that simple, but nope. There are errors on the page itself, the ephone_admin.html page comes up with errors.
If I click on add a phone I get the two phones that are registered in the drop down box, go through the motions of setting the fields, add a PIN and user, click add, get the popup to save and then nothing, but on the main screen there is the error icon in the left corner. I think something got fragged during install. Going to wipe the flash and start over using 22.214.171.124 for the GUI instead.
I'm experiencing this with 12.4(15)T5 and GUI 126.96.36.199 (Compatible with IOS 12.4(15)T). I was able to add a lot of phones before when I was first setting the system up, but I'm now coming across this same error.
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.