When trying to serialize an object that contains unserializable data, cxf runs into an exception.
An error log message is printed by `JAXRSUtils.logMessageHandlerProblem`. However, the message contains no stack trace. On top of that the invoking client receives a `200 OK` HTTP status code and partially written JSON, followed by an error message.
What I'd have expected instead, is to use the registered `ExceptionMapper`, which would turn this into an `500 Internal Server Error`. On top of that, it should print the stacktrace, as it's pretty hard to know what's going on otherwise.
In our specific case, we had an object that contains a `java.awt.Font` object.