Cannot create a session after the response has been committed

Question

Opening the JSF page gives me the following exception:

Caused by: java.lang.IllegalStateException: Cannot create a session after the response has been

Answer 1

[SOLVED]

It took days to diagnose this problem, but finally I am able to solve this problem.

It was actually @ViewScoped and it has a managed property DAO object which was not serialized. So after view is rendered, facelets also produce this exception, but JSF view already rendered and that's why this exception showed.

Solution: Make all objects serialized in @ViewScoped bean, and mark "transient" who are not serialized like in my case it was DAO object in JSF @ViewScoped.