Is this a custom cache loader you've written? The warning is for people who have written custom cache loaders to the CacheLoader interface prior to JBoss Cache 1.3.x. Since 1.3.x, the interface contract as changed with regards to what a CacheLoader.get() should return. Since you're using 1.4.x, I don't think this will apply to you if you have read the CacheLoader interface javadocs and have implemented your cache loader to adhere to this contract. Cheers, Manik View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4085641#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...