Hello. I have a problem with zone.js.
I am using Liferay portlets. In one portlet I had a vaadin portlet and in other portlet i have a portlet portlet who use zone js.

Using the vaadin portlet (for example clicking a button) in some cases i got a "Converting circular structure to JSON". Stack:

GMT-300 2016 com.vaadin.client.ApplicationConfiguration
SEVERE: (TypeError) : Converting circular structure to JSON
com.google.gwt.core.client.JavaScriptException: (TypeError) : Converting circular structure to JSON
at Unknown.yfb(test.vaadin.view.ViewDashletWidgetset-0.js)
at Unknown.Uj(test.vaadin.view.ViewDashletWidgetset-0.js)
at Unknown.Lj(test.vaadin.view.ViewDashletWidgetset-0.js)
at Unknown.tj(test.vaadin.view.ViewDashletWidgetset-0.js)
at Unknown.sj(test.vaadin.view.ViewDashletWidgetset-0.js)
at Unknown.eval(test.vaadin.view.ViewDashletWidgetset-0.js)
at Unknown.wrapFn(http://localhost:8380/o3-parts-web/angular-dashlet/js/polyfills.js?cache=false)
at Unknown.invokeTask(http://localhost:8380/o3-parts-web/angular-dashlet/js/polyfills.js?cache=false)
at Unknown.runTask(http://localhost:8380/o3-parts-web/angular-dashlet/js/polyfills.js?cache=false)
at Unknown.ZoneTask.invoke(http://localhost:8380/o3-parts-web/angular-dashlet/js/polyfills.js?cache=false)
Jgb @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:60233uhb @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:33851thb @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:16817iZd @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:5172iCb @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:62420wj @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:16980Uj @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:27567Lj @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:15246tj @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:13234sj @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:28285(anonymous function) @ test.vaadin.view.ViewDashletWidgetset-0.js:formatted:22140wrapFn @ zone.js:855ZoneDelegate.invokeTask @ zone.js:262Zone.runTask @ zone.js:151ZoneTask.invoke @ zone.js:332

Without zone.js in the same page, Vaadin portlet works well.

Any idea why zone.js could generate this error?

Thanks
Diego