Calling a view from the menu or from another view

Hello everyone.
What is the way to get a view defined by the developer from the main menu or from another view?
When I try to do is give me the error I should use openWindow () or OpenEditor (). My class extends from AbstractWindow.
Where I can find examples with previous cases?

Thank you.

Nelson F

Hi Nelson,
First, take a look at this example (it is also available directly from Studio samples).
Second, if you need to open a screen from main menu, use the main menu designer of Studio or edit your web-menu.xml directly, see
If you get an exception when invoking a screen, please provide your code and the stacktrace.