Data Prep Free Desktop "Access denied" issue or proxy problem


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 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:

  • Preferably: a loopback adapter (specialized in handling TCP/IP communications on
  • An exception in the proxy and/or firewall settings to allow connections on
Version history
Revision #:
2 of 2
Last update:
‎09-29-2018 12:15 AM
Updated by:
Labels (2)