ConcurrentModificationException when 2 IAs and 1 tower

[timriom]

Exception in thread "main" java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
at java.util.AbstractList$Itr.remove(AbstractList.java:357)
at renderer.Renderer.refreshView(Renderer.java:115)
at dispatcher.Dispatcher.main(Dispatcher.java:165)