I came across a similar Exception with the 1.2.0Patch1 release (I haven't tried this on 1.2.1 yet). In short, some fields in my tables were deliberately of type char (rather than varchar) to test out seam-gen and even though the entity beans were reveng'ed by seam-gen, the expected type for those same fields on the deployed app was varchar. In my case I was able to fine-tune the schema this time, but I never got an answer to my question about what to do when the schema is fixed (eg a client's legacy app that has some fields defined as char(n)). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4033469#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...