Exception occurs when re-opening a saved .xml file with a mouse

[jyoshimi]

Here is the file in question

ProtoWorld.xml.zip

And the exception on my machine.
[java] java.lang.NullPointerException
[java] at org.simbrain.world.threedworld.entities.WalkingEffector.updateAnimation(WalkingEffector.java:245)
[java] at org.simbrain.world.threedworld.entities.WalkingEffector.update(WalkingEffector.java:232)
[java] at org.simbrain.world.threedworld.entities.Agent.update(Agent.java:158)
[java] at org.simbrain.world.threedworld.ThreeDWorld.update(ThreeDWorld.java:173)
[java] at com.jme3.app.state.AppStateManager.update(AppStateManager.java:287)
[java] at org.simbrain.world.threedworld.engine.ThreeDEngine.update(ThreeDEngine.java:303)
[java] at org.simbrain.world.threedworld.engine.ThreeDContext.updateInThread(ThreeDContext.java:181)
[java] at org.simbrain.world.threedworld.engine.ThreeDContext.access$1(ThreeDContext.java:163)
[java] at org.simbrain.world.threedworld.engine.ThreeDContext$Listener.update(ThreeDContext.java:33)
[java] at com.jme3.system.lwjgl.LwjglOffscreenBuffer.runLoop(LwjglOffscreenBuffer.java:125)
[java] at com.jme3.system.lwjgl.LwjglOffscreenBuffer.run(LwjglOffscreenBuffer.java:151)
[java] at java.lang.Thread.run(Thread.java:745)
[java]