Hello oskar, First thanks for replying. I am using Required transaction attribute when i am creating a transaction with Spring. This behaves the same way as the Required transaction attribute in CMT. And the transaction attribute in the EJB is also "Required". So in theory there must not be a new transaction which should be created by Spring and the same transaction which has been created by the EJB must be used. My application runs fine for a long time and then suddenly this error pops up and then all the following request fail with the same error. If Jboss is restart then it is working fine again. Please let me know your comments. Thanks & Regards, Subramaniam V View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4091412#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...