I keep getting this annoying crash

[King]

I know, when I use Buildism, I use the terrain tool and when I press, it just crashes! Infact, it neally happens with every tool! This is the crash code I got:

java.lang.ArrayIndexOutOfBoundsException: 2147483647
org.jbox2d.collision.BroadPhase.a(BroadPhase.java:242)
org.jbox2d.collision.a.l.b(Shape.java:349)
org.jbox2d.dynamics.Body.a(Body.java:386)
net.buildism.object.Terrain.drawHeightmap(Terrain.java:363)
net.buildism.object.Terrain.addToWorld(Terrain.java:156)
net.buildism.aa.a(World.java:475)
net.buildism.object.GameObject.onParentChanged(GameObject.java:386)
net.buildism.object.GameObject$2.handle(GameObject.java:123)
net.buildism.object.GameObject.onPropChanged(GameObject.java:633)
net.buildism.object.GameObject.setProp(GameObject.java:461)
net.buildism.object.GameObject.setProp(GameObject.java:495)
net.buildism.object.GameObject.setParent(GameObject.java:507)
net.buildism.aa.b(World.java:636)
net.buildism.a.b.a(DefaultInputProcessor.java:319)
net.buildism.l.p(Main.java:751)
net.buildism.MainApplet.run(MainApplet.java:210)
java.lang.Thread.run(Unknown Source)