If you use myfaces-1.1.5, you might have seen this error in you console. There are not too many sites presenting information about what’s causing this, and I struggled a bit myself trying to find out why my javascript console was flooded with this error message for each submit I did.
The problem appears if you have the org.apache.myfaces.AUTO_SCROLL parameter set to true, and you submit a form with one commandButton only. There is a JIRA-issue on it here, if you want some more specific information: MYFACES-1504. To give an example, this page would produce an error if AUTO_SCROLL is enabled:
<h:form id="myForm"> <t:commandButton id="submitMyFormButton" value="Submit" action="#{myHandler.myAction}" ></t:commandButton > </h:form>
There are no fixes to this problem yet (as of 20.01.2008), so until there is a version where this is corrected, simply add a hidden commandLink to the same form, and the problem goes away. You can’t hide it with the rendered attribute if myfaces, but have to hide it with css and styling:
<h:form id="myForm"> <t:commandButton id="submitMyFormButton" value="Submit" action="#{myHandler.myAction}" ></t:commandButton > <t:commandLink id="stupidHiddenButtonToAvoidException" value="Nothing" style="display: none; visibility: hidden;"></t:commandLink> </h:form>