To use my Harmony Hub with Indigo and the Harmony Hub Plugin I had to enable XMPP on my Hub. Basically all bets were off until I did this. It was easy to do but took be quite a bit of time to find it....
On your phone app go to the "hamburger" menu in the top right side of the screen. Tap Harmony Setup -> Add/Edit Devices & Activities -> SETTINGS -> HUB -> ENABLE XMPP
Where did I find the info?
https://support.logi.com/hc/en-001/comm ... I-via-XMPP
This was suggested in another post but I think the URL had changed. I searched support.logi.com for "Update-to-accessing-Harmony-Hub-s-local-API" and found it pretty quickly. You can get the whole story about why XMPPwas locked down at that link too.
What is XMPP?
Extensible Messaging and Presence Protocol is a communication protocol for message-oriented middleware based on XML. It enables the near-real-time exchange of structured yet extensible data between any two or more network entities. - Wikipedia
Joe... you are awesome! Thanks for the excellent plug-in!