javax.servlet.jsp.JspException: Argument Error: One or more parameters are null ?

This is not a very descriptive exception. A parameter in your page is null. You should verify the attributes of the JavaServer Faces components of your page. If you are not sure which component is concerned open the generated java source of your jsp and jump to the lines indicated in the exception.

After you narrowed the trouble down to component level, verify if the are any attributes that could possibly be null, or if there are any attributes missing that should be there.


Checklist:
* Verify if there are any attributes that could possibly be null.
* Verify if there are any attributes missing.
* Verify if you have missed to specify an "itemLabel" attribute for a .
* If you use resource bundles for an attribute double-check its spelling, because this exception can *hide* a bundle spelling problem.
* Restart your web application in order to see if the problem persists.