Since I am not able to post a comment into the jira ticket I like to announce, that the same things happen when having the gravel lib in the classpath. In this case, the seam multipart request is replaced by the GravelHttpServletRequest. I found this by debugging FileUploadRendererBase.doDecode(). The result is the same as with the trinidad libs. The setter for the byte[] is called with a null value. Anyway, is there a workaround? Bye, daniel View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4114975#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...