So I paid to get the latest version, however, I wasn't able to get the XenCentral Framework which is essential to run it. I left a ticket in the members area, but paying for something and then having to wait, it's not the 90's!
Ok, so it's not that big a deal, however, I hope by putting a review here I will make sure others don't suffer this fate.
Specifically, I bought the €15 support package so I could get the latest version and talk to someone about getting XenCentral Framework which seems a bit of a cheat that I WOULD NEED the support to download it, but have to pay for it.
There were no cases when our customers had issues with invitation not working and we couldn't find the reason. Please contract us and provide your Ticket ID and we will review it again. The invitations definitely work as they are advertised if you have everything properly configured. The only known issue is Facebook invites not being sent on some servers which block XMPP requests, and one can do nothing with it but to configure server firewall to allow XMPP protocol usage.
Thank you!