java.lang.Exception: The model extension definition cannot be added to the registry because it has 1 parsing errors. This is the first error: "cvc-elt.1: Cannot find the declaration of element 'p:modelExtension'."
	at org.teiid.designer.extension.registry.ModelExtensionRegistry.addDefinition(ModelExtensionRegistry.java:107)
	at org.teiid.designer.extension.ExtensionPlugin$2.run(ExtensionPlugin.java:316)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.teiid.designer.extension.ExtensionPlugin.loadBuiltInMeds(ExtensionPlugin.java:322)
	at org.teiid.designer.extension.ExtensionPlugin.start(ExtensionPlugin.java:403)
	at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:711)