Revision History selection results in exception richtext.jcr.RichTextImageURLProvider.getURL(

Steps to reproduce
1) Login CMS Go Green Enterprise
2) Go to /content/documents/hippogogreen/jobs/solar/solarcooking---what-can-you-do
3) Edit / Publish the document a few times
4) Go to Document/Revision History and select a version from the list:
Expected: Old version selected
Actual: No response. Stacktrace:

[INFO] [talledLocalContainer] Caused by: java.lang.RuntimeException: An error occurred while getting the model object for Component: [HtmlContainer [Component id = view, page = org.hippoecm.frontend.PluginPage, path = 1:root:tabs:panel-container:cards:2:panel:center:tabs:panel-container:cards:1:panel:editor:extension.editor:template:extension.left:view:3:item:view:1:item:cmp:panel:view.HtmlContainer, isVisible = true, isVersioned = false, markup = [markup = jar:file:/home/abanck/svn/gogreen-enterprise/target/tomcat7x/webapps/cms/WEB-INF/lib/hippo-cms-richtext-frontend-2.25.04-SNAPSHOT.jar!/org/hippoecm/frontend/plugins/richtext/view/AbstractRichTextViewPanel.html
[INFO] [talledLocalContainer] <wicket:container wicket:id="view"></wicket:container>, index = 0, current = '<wicket:container wicket:id="view">' (line 0, column 0)]]]
[INFO] [talledLocalContainer] at org.apache.wicket.Component.getDefaultModelObject(Component.java:1629)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.richtext.view.AbstractRichTextViewPanel$HtmlContainer.onComponentTagBody(AbstractRichTextVie

[INFO] [talledLocalContainer] Caused by: java.lang.NullPointerException
[INFO] [talledLocalContainer] at java.util.TreeMap.getEntry(TreeMap.java:342)
[INFO] [talledLocalContainer] at java.util.TreeMap.containsKey(TreeMap.java:227)
[INFO] [talledLocalContainer] at java.util.TreeSet.contains(TreeSet.java:234)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.richtext.jcr.RichTextImageURLProvider.getURL(RichTextImageURLProvider.java:50)
...