Edilmar Alves, we've had multiple users state that bumping Javassist up to 3.18.1 resolved the issues. If 3.18.1 is truly being used, the "cannot be cast to javassist.util.proxy.Proxy" doesn't make much sense. Are you 100% positive that your app has only 3.18.1 in the classpath (ie, is another version provided by the container, another dependency, etc.)?

If someone has a reproducer to attach (standalone, not requiring glassfish to reproduce the error), I'd be happy to work with it.