ArrayIndexOutOfBoundsException thrown when browsing

When clicking through the faceted reference portion of the reviewed action application, there are regular occurrences of ArrayIndexOutOfBoundsException.
Mini stack:

WicketMessage: Exception in rendering component: [MarkupContainer [Component id = link, page = org.hippoecm.frontend.Home, path = 0:rootPlugin:navigationPlugin:tree:i:29:link.DefaultAbstractTree$4, isVisible = true, isVersioned = false]]

Root cause:

java.lang.ArrayIndexOutOfBoundsException: -2
at java.util.ArrayList.get(ArrayList.java:323)
at org.hippoecm.frontend.model.JcrTreeNode.getChildAt(JcrTreeNode.java:63)
at org.apache.wicket.extensions.markup.html.tree.DefaultAbstractTree.isNodeLast(DefaultAbstractTree.java:619)
at org.apache.wicket.extensions.markup.html.tree.DefaultAbstractTree.access$000(DefaultAbstractTree.java:58)
at org.apache.wicket.extensions.markup.html.tree.DefaultAbstractTree$2.onComponentTag(DefaultAbstractTree.java:369)
at org.apache.wicket.Component.renderComponent(Component.java:2377)
at org.apache.wicket.MarkupContainer.onRender(MarkupContainer.java:1355)
at org.apache.wicket.Component.render(Component.java:2254)
...