I think I see the problem. We do this with a complex type but we use a custom deserializer that already "knows" what Java type it works with. Because BeanSerializer is generic, it has to determine the Java type from the mapping. To do that it calls XMLJavaMappingRegistry.queryJavaType, which throws this error when it fails.
I think this will work if you add the javaType element into your type mapping. Beware that in our experience whenever Apache SOAP has to serialize a type for sending, it uses the last mapping defined in the deployment descriptor for that type, so this "deserialize only" mapping has to occur first (if you ever send this type). ..Dave Reid
