Googla AppEngine [production server junks LocalVariableTable information, but the dev appserver does not, to allow for better debugging. Javassist instrumentation for @Property, etc., causes bad LVT information to be written into the bytecode, causing components/pages to not be loadable in the developer appserver, including stock components such as Form.
Javassist 3.12.0.GA fixes many of these problems. Updating to 3.12.0.GA in the pom.xml dependencies would be ideal.
Blocking: 3.12 has not been pushed to jboss's (nor central's) repositories.