java.lang.IllegalStateException: Illegal attempt to set ViewHandler after a response has been rendered

Question

My Java EE web application is working fine with Glassfish 2.1. Now I want to migrate to Glassfish 3.1.1, but after a successful deployment of the war file it gives following

Answer 1

I had to remove the Ajax4jsf library from my application before I could get this error to go away. Evidently, the Ajax4jsf library is not compatible with JSF 2.0.

Here where I found this.
Migrating JSF 1.1 with Ajax4jsf-1.x to JSF2