GWT has an internal version to make sure client and server can speak with each other correctly. Currently your client side code talks "version 7" but your server code only understands "version 5 and 6". I would say you have upgraded to a newer version of GWT (e.g. 2.3.0) but your IDE does not have updated GWT's server side libraries (gwt-servlet.jar and possibly gwt-servlet-deps.jar) in you WEB-INF/lib folder.
Copy the new files into your WEB-INF/lib folder, rebuild your app and it should work. -- J. -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to google-web-toolkit@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
