Hello, I read a little the other questions about this but I got something different I think. I am following the starter tutorial ‘Vaadin step-by-step’ and when I try to create a vaadin component it opens up like I showed in the attach. I can open the source and I get the java code but the editor is not showing. This is the first time for me using Vaadin 
OK I found the solution by myself. The suport should be a little more good than this I think 
1- Before opening eclipse go to " https://developer.mozilla.org/en-US/docs/XULRunner_1.9.2_Release_Notes "
2- Extract the contents to C:\ .A folder ‘xulrunner’ should be created.
3- In eclipse directory open eclipse.ini file
4- Add this line: -Dorg.eclipse.swt.browser.XULRunnerPath=C:\xulrunner
5- Start your eclipse and add a Vaadin Composite to your project
If a popup shows up “Could not start XULRunner. . … . . .” just press OK. Till now it works well for me.