Hi, after doing tutorials 1 through 3, I notice I get the following error every 
time I execute
java sim.app.tutorial1and2.tutorial2

The error is detailed below, not sure what to make of it.
---
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:5
7)
	at 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorIm
pl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	at sim.display.GUIState.getName(GUIState.java:118)
	at sim.display.Console.buildClassList(Console.java:1743)
	at sim.display.Console.<init>(Console.java:935)
	at sim.display.GUIState.createController(GUIState.java:138)
	at sim.app.tutorial3.Tutorial3WithUI.main(Tutorial3WithUI.java:22)
Caused by: java.lang.Error: Unresolved compilation problem: 

	at sim.app.crowd3d.Crowd3DWithUI.getName(Crowd3DWithUI.java:43)
	... 9 more
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:5
7)
	at 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorIm
pl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	at sim.display.GUIState.getName(GUIState.java:118)
	at sim.display.Console.buildClassList(Console.java:1743)
	at sim.display.Console.<init>(Console.java:935)
	at sim.display.GUIState.createController(GUIState.java:138)
	at sim.app.tutorial3.Tutorial3WithUI.main(Tutorial3WithUI.java:22)
Caused by: java.lang.Error: Unresolved compilation problem: 

	at sim.app.pso3d.PSO3DWithUI.getName(PSO3DWithUI.java:36)
	... 9 more