Prior to release 1.0.4, none of the standard Log implementations were Serializable. If you are using such a release and have a Serializable class with a member that is of type Log then it is necessary to declare that member to be transient and to ensure that the value is restored on deserialization. The recommended approach is to define a custom readObject method on the class which reinitializes that member. In release 1.0.4, all standard Log implementations are Serializable. This means that class members of type Log do not need to be declared transient; on deserialization the Log object will "rebind" to the same category for the same logging library. Note that the same underlying logging library will be used on deserialization as was used in the original object, even if the application the object was deserialized into is using a different logging library. There is one exception; LogKitLogger (adapter for the Avalon LogKit library) is not Serializable for technical reasons. Custom Log implementations not distributed with commons-logging may or may not be Serializable. If you wish your code to be compatible with any arbitrary log adapter then you should follow the advice given above for pre-1.0.4 releases. http://commons.apache.org/logging/guide.html#Serialization%20Issues I'm running JBoss 4.2.1.GA which has 1.2.14 of log4j in the default/lib. There is no log4j jar in my EAR. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4102318#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...