Here’s an update.
I found that the Class com.webMethods.caf.faces.google.ui.preferences.GooglePreferencePage is missing in the Plugin. (See attached image).
Is there something that I have missed in the procedure to add this plugin?
!ENTRY com.webmethods.caf.faces.google.ui 4 4 2009-11-06 13:28:24.808
!MESSAGE ExtensionsUIPlugin.InternalError
!STACK 0
org.xml.sax.SAXParseException: The markup in the document following the root element must be well-formed.