Friday, October 22, 2010

Session Expired error in Vaadin and Google App Engine

When developing a Vaadin RIA web application on Google App Engine and you get the following error when clicking a button or any UI action:

Session Expired
Take note of any unsaved data, and click here to continue.

90% of the time it means your program throws an Exception.

So check the Console for exceptions and fix it.

1 comment:

  1. I dont think this is because our program throws exception . Most of the time if some process is taking more time then this error comes .I have tried increasing the session timeout to avoid this but that is of no use.