https://www.infopathdev.com:443/forums/46.aspx For questions concerning issues in the integration of SharePoint and Microsoft InfoPath.enCommunityServer 2007 SP3 (Build: 31118.962)https://www.infopathdev.com:443/forums/thread/88565.aspxTue, 02 Apr 2013 01:41:00 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:88565Mel Clemente0https://www.infopathdev.com:443/forums/thread/88565.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=46&PostID=88565<p>Both the fields that are using dropdown list boxes should be bound to your main data source. Is this not the case? If you don&#39;t mind, please attach your XSN here so we can take a look.</p>https://www.infopathdev.com:443/forums/thread/88468.aspxThu, 28 Mar 2013 17:14:04 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:88468chrisgee0https://www.infopathdev.com:443/forums/thread/88468.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=46&PostID=88468I get this error when trying to publish a browser-enabled form. The full error is &quot;The filter expression is on external data and could not be validated. It may not be supported in Web browser forms.&quot; This is happening because I have cascading drop-down lists that are populated from a Sharepoint List. The second drop-down filters its list items based on user selection in the first list. I guess Infopath can&#39;t properly validate the filter because the data exists on these external lists but there must be some way to do this. I read <a href="http://social.technet.microsoft.com/forums/en-US/sharepointcustomizationprevious/thread/7951d3ca-0614-4f8b-bfdc-49862dccb336/">Clayton Cobb&#39;s answer</a> and see that I might be able to add something to the Form Load rules, but my list is much more complex than the example given.