Found it, the "appId": "", in the config files was the wrong one.
This is my development cycle:
- create application in Web Application Builder in my workstation,
- download the application locally, create a virtual directory in IIS in my workstation pointing to it
- open the web application with Visual Studio 2012, using the option "Open web Site" and customize it in my workstation
- with Visual Studio 2012, publish the application on the development server (a testing server), in order to be tested by the users
- deploy to production server when end users approve the application or enhancements
Thanks