The optional object returned from the optional argument returned from the observable used in: data.getProc().taskExeced.addObserver Is a TaskEvent class. TaskEvent is not public, and therefore the optional argument passed to the observer is not castable as TaskEvent. As noted, the short term fix was to change frysk.proc.TaskEvent to public. This has been completed. However making TaskEvent public exposes too much information outside of the class.
With the addition of all the observers, this is "fixed".