NullPointerException ...gwt.client.MouseEvent (on Vaadin 6.6.1)


After I upgrade my Vaadin from 6.5.3. to 6.6.1, I get a NullPointerException on every button click!

Do you have any solution, why? Bug or feature?

at com.vaadin.terminal.gwt.client.MouseEventDetails.deSerialize(
at com.vaadin.ui.Button.changeVariables(
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariableBurst(
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariables(
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.doHandleUidlRequest(
at com.vaadin.terminal.gwt.server.CommunicationManager.handleUidlRequest(
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(
at javax.servlet.http.HttpServlet.service(
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(
at org.apache.catalina.core.ApplicationFilterChain.doFilter(
at org.apache.catalina.core.StandardWrapperValve.invoke(
at org.apache.catalina.core.StandardContextValve.invoke(
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(
at org.apache.catalina.core.StandardHostValve.invoke(
at org.apache.catalina.valves.ErrorReportValve.invoke(
at org.apache.catalina.valves.AccessLogValve.invoke(
at org.apache.catalina.core.StandardEngineValve.invoke(
at org.apache.catalina.connector.CoyoteAdapter.service(
at org.apache.coyote.http11.Http11Processor.process(
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(
at java.util.concurrent.ThreadPoolExecutor$




when you are using any custom client-side code (including add-ons from the
), you should always recompile your widgetset when updating your Vaadin version. My guess is that this might be the cause of your NPE .

  • Teemu

Thanks, but when I recomplie
my Widgetset:

Because why?


You are trying to compile with an old version of GWT. If you are using Vaadin Eclipse plug-in to compile the widgetset, try to switch your project’s Vaadin version to an older version and then back to 6.6.1 to update GWT.

Which version of the GWT libraries are you using? Vaadin 6.6.1 requires GWT 2.3.

If you are using the Vaadin Plugin for Eclipse for the compilation, you should first upgrade the plugin to the latest version.

  • Teemu


I update gwt to 2.3 and than I recompile with eclipse plug in:
i chance in my lib directory the gwt-usr, gwt-dev and the gwt-dev-tooling too:

But the result is the same:

Whats wrong?


Try to add "
" parameter to the URL to display a debug window (for example
). In the debug window you can see a line indicating which Vaadin version your widgetset was built with. In this case it should display a line “Widget set is built on version: 6.6.1”

Have you restarted your server after the recompilation?

  • Teemu


Starting from GWT 2.3, GWT want’s along with the dev and user libs also the validation-api and validation-api-sources libs. Adding that should at least remove some of the problems.

Hey !
Thanks to all of you for your support!

But nothing solve my problem, I will get always the same error!

Now I store my resoures for later and delete my widgetsets, and I will try to develop new widgetsets in order it solves my problem!

So I can run my the rest of my application without exceptions, at the moment.

I hobe it will the best workarround at least for now and for me!


I also believe that this is the problem of having old widgetset with newer Vaadin version.

That said - the cause for the NPE was
in Vaadin 6.6.2, so try updating to that version.

I have done so