(TypeError) : Cannot read property 'layout' of null

I am getting this error in my application:

(TypeError) : Cannot read property ‘layout’ of nullcom.google.gwt.core.client.JavaScriptException: (TypeError) : Cannot read property ‘layout’ of null
at Unknown.l9d(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.$8d(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.cl(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.Vk(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.gl(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.al(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.yk(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.Bk(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.eval(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)
at Unknown.d(com.ixiacom.volcano.gui.vaadin.VolcanoWidgetSet-0.js)

I have no idea where it is thrown from or what is causing it. The error is thrown when I change the visibility of a component. However I get no error with that functionality until I modify other components in another layout. So I am not sure how to find the relationship.

How do I go about debugging this?? The error message is quite obfuscated I’m stomped. Any suggestions would be appreciated!

If you are using Eclipse and the Vaadin Plugin for Eclipse, you can get nicer client-side errors by setting the JavaScript style as “Pretty” instead of the default “Obfuscated”, and then recompile the widget set. Also the Vaadin ?debug window could give you some more info.

The most common way to get client-side errors like that is to not have compiled the widget set after updating some libraries (Vaadin libraries or add-ons containing client-side code). The ?debug window can warn you at least about mismatching Vaadin and widgetset versions.