This does not throw an exception due to the behavior of an s:link. An s:link initiates a GET request which will only capture parameters passed in the query string (nothing is posted). If you look at the URL generated by your s:link you will see something like the following: .../page2.seam?conversationPropagation=begin As you can see, there is no conversationId included in the URL. This would indicate to Seam that a long-running conversation does not exist so promote the temporary conversation to long-running. This could either be a feature or a bug depending on how you look at it. I could imagine situations where this may be a useful feature, but it could definitely be confusing unless you know the finer details. In the case where you use join="true", the s:link will send the conversationId as part of the query string: .../page2.seam?conversationId=1&conversationPropagation=join Obviously if propagation="join" Seam looks for an existing long-running conversation when rendering the s:link (in contrast to propagation="begin"). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4096107#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...