Hello, I've used today p:birt tag with embed - just like in the sample : <b:birt designType="embed" designName="ProductCatalog.rptdesign" | embeddable="true" masterpage="false"/> I have in the same JSF page a form with h:commandButton. On first render, everything works fine. On postback, birt tag generates an error (I dont remember exactly which one). The line in error was in UIDocument#encodeBegin because designNameValue was null on postback : buffer.append(URLEncoder.encode(designNameValue,"UTF-8")); This is due because saveState and restoreState are not implemented in org.jboss.seam.birt.ui.UIDocument (just look at http://fisheye.jboss.org/browse/~raw,r=11184/JBossTools/trunk/birt/plugin... for instance). You should save the state of all the attributes in saveState method otherwise they are going to be null on every postback. A second bug : some attributes are missing in saveState and restoreState of UIParameter (locale, isnull). Should I fill a JIRA issue ? Thanks ! View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4253158#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...