My name is Jacob, and I'm an engineer from the DevNet Sandbox team. I will try to replicate your issue and see if I'm getting the same error. I'll get back to you once I've tried this out.
Just one question. What operating system are you using? It appears that you're using Jabber Guest for Mac but I just want to be sure when replicated the issue.
Thank you for reaching out to us. In addition to Jacob's question, what version of Chrome are you running?
Dear Jabber Guest Sandbox alias members, I was using Chrome and when instructed to download Jabber Guest Add-On from https://jabberguestsandbox.cisco.com/call/JabberGuest-add-on_for_Mac-Version_10.6.12.1.dmg
Jab Guest Add-On during installation reported following error "Protocol wrong Type Socket" and lab was not working.