I didn't download any driver for my flexKey because it seems be detected by ubuntu (as you can see in the attached file "dmesg.txt").
I executed start.sh and I obtained the output you find attached as "out.txt" file. In the http://localhost:8080/demo/conf/index.html?lang=en URL, after the login, I received the message: "Problemi con l'adattatore ZigBee".