WinXP/WAS 6.1.0.3 All the jbosscache required libraries are copied in AppServer/lib/ext - and will be loaded by the extension classloader. I've created a CustomService JbossCache is configured with CacheMode REPL_SYNC. Whatever is put the cache are classes loaded by one of the application class loader. Whenever jboss-cache tries to deserializes content it says it can't find the class - which is normal. The only UGLY workaround is to load the classes put in cache with the same or higher classloader, or use INVALIDATION_SYNC as CACHE_MODE and then no application content is sent accross. Do others have different ideas ? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4025416#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...