Error: No window found. Did you remember to setMainWindow

We have a small tool/application written in Vaadin in our production environment. It has been very stable so far. Recently, a user reported an error that occurred randomly. The application was up and running and while he was using it to fill out a form, the error occurred. This was the logfile output. Any idea why this would happen? Has anyone else experience this? Our production machine is using vaadin-6.1.5.

[2010-07-16 14:34:21.272]
javax.servlet.ServletException: javax.servlet.ServletException: No window found. Did you remember to setMainWindow()?
[2010-07-16 14:34:21.272]
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.handleServiceException(
[2010-07-16 14:34:21.272]
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(
[2010-07-16 14:34:21.272]
at javax.servlet.http.HttpServlet.service(
[2010-07-16 14:34:21.272]
at com.caucho.server.dispatch.ServletFilterChain.doFilter(

After opening a new browser window, the error was gone.


Greetings Tara Doney,

did you check if the posted error was solved?
you error was checked for servlets, in this case, i’m using portlets
i’m developing vaadin portlets using portlet 2 spec and liferay portal 6.0.5.
the problem was detected using vaadin framework 6.4.8.
I already put my problem into a ticket for revision (
See ticket 6164