> On Apr 29, 2018, at 11:57 AM, Brant Horio <[log in to unmask]> wrote: > > MASON Version 19. For further options, try adding ' -help' at end. > Exception in thread "Thread-0" java.lang.RuntimeException: Exception occurred while trying to construct the simulation class model.VaxHedge_Controller > java.lang.reflect.InvocationTargetException > at sim.engine.SimState$1.newInstance(SimState.java:365) > at sim.engine.SimState$2.run(SimState.java:608) > at java.lang.Thread.run(Unknown Source) Unfortunately, SimState's code isn't helpful here -- it didn't attach the cause of the InvocationTargetException so you could see what's going on. I just committed a new version of SimState. try grabbing MASON from the repository and running it again. Or you could just edit line 365 of SimState.java to say: throw new RuntimeException("Exception occurred while trying to construct the simulation " + c, e); Sean