NullPointerException from RestoreViewPhase.notifyAfter

I'm getting the following error whenever I try to view JSF pages that 开发者_JAVA技巧contain forms.

java.lang.NullPointerException
    com.sun.faces.lifecycle.RestoreViewPhase.notifyAfter(RestoreViewPhase.java:288)
    com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:110)
    com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
    org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:349)

What does this mean?

This problem started when I tried to use validators on my form fields. So I removed all the validators, but still the problem is not going away.

Thanks for the help.

Could be this logged issue: http://java.net/jira/browse/JAVASERVERFACES-1764

If that is the case then it should be fixed in JSF version 2.1.