I am running Odoo 9 on Debian 8 proxied with nginx SSL.

I have Etherpad-Lite running with it's internal SSL on https://servername.com:9001

I am able to access both Odoo and Etherpad from Firefox, Chrome and Opera, but the Project --> Task --> Edit button gives me the error: Pad creation failed, either there is a problem with your pad server URL or with your connection.

Neither the Odoo or ngnix logs have errors, and when I disable the etherpad SSL (and change the Pad Server url back to http:// in Company Configuration ) I can edit pads (using Opera and allowing insecure content). 

Am I missing something in the odoo config? Is there some way to troubleshoot this that I haven't seen?

Update:

I've found the following code in addons/pad.py

I tried changing the 'http' to 'https' and running odoo.py --update=all and reinstalling the Collaborative Pads app but am receiving the same error.

Looks like that code is just there to append a http(s): if it's not already there (I tried without http:// in Company Settings --> Pads --> Pad Server to no avail).