Error when serving the basic "Type your name here" demo application.

Vaadin 6 / 7 / 8
1

When trying to serve the basic starting Maven app from a WAR file (the one that gives the message “Type your name here” and then has a button “Click Me”), the GUI only shows a loading graphic and gives the following error on the client side browser:

Uncaught SyntaxError: Unexpected token G in JSON at position 0
at JSON.parse ()
at XMLHttpRequest.r.onreadystatechange (vaadinBootstrap.js?v=8.1.6:168)

I’m not sure how to proceed in trying to figure out what is going wrong and wonder if anyone has experience with this issue.

The server is IIS with Tomcat.

2

It looks like you have a problem with IIS settings. Some requests are not being forward from server (Tomcat) to browser in correct way, thus you get this exception.