You might experience network connectivity issues such as proxy problems or "Access denied". This should not happen, as Talend Data Prep Free Desktop makes no Internet connections and receives no connection from outside the local computer (except when sending feedback through the feedback form). Everything runs on the local machine, which may therefore be 100% offline.
Data Prep stand alone desktop edition.
It is a requirement that Data Prep be able to connect to 127.0.0.1 on port 9090 for INTERNAL communication. In fact, Data Prep is an HTML 5 Web UI connected to a downsized, embedded web server.
The software performs only internal HTTP calls, so it is very strongly recommended that it use a local loopback instead of a real online network connection through the wireless or ethernet adapters — for obvious performance reasons.
Confirm with your local IT that your computer has: