"adrian(a)jboss.org" wrote : The reason I think it will be difficult to reproduce the problem is because I think this only occurs when you hit the ClassCircularity bug. Perhaps the mod_cluster objects being deserialized trigger the ClassCircularity bug? That may explain why Bela is seeing this with mod_cluster while we haven't gotten a ton of reports on it for AS 5. Still trying to reproduce... Bela said it wasn't that hard for him to reproduce by stumbling into it, so if I can't there's a reasonable chance he'll be able to. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206702#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...