[196868] Mechanism for obtaining the substitution group value of an element declaration via the content model is required.  Second patch.  Check patch into HEAD.
diff --git a/bundles/org.eclipse.wst.xsd.core/src-contentmodel/org/eclipse/wst/xsd/contentmodel/internal/XSDImpl.java b/bundles/org.eclipse.wst.xsd.core/src-contentmodel/org/eclipse/wst/xsd/contentmodel/internal/XSDImpl.java
index 1b18258..6b006c1 100644
--- a/bundles/org.eclipse.wst.xsd.core/src-contentmodel/org/eclipse/wst/xsd/contentmodel/internal/XSDImpl.java
+++ b/bundles/org.eclipse.wst.xsd.core/src-contentmodel/org/eclipse/wst/xsd/contentmodel/internal/XSDImpl.java
@@ -1839,7 +1839,16 @@
      */
     public String getSubstitutionGroupValue()
     {
-      return getResolvedXSDElementDeclaration().getElement().getAttribute(XSDConstants.SUBSTITUTIONGROUP_ATTRIBUTE);
+    	XSDElementDeclaration xsdElementDeclaration = getResolvedXSDElementDeclaration();
+    	if(xsdElementDeclaration != null)
+    	{
+    		Element element = xsdElementDeclaration.getElement();
+    		if(element != null)
+    		{
+    			return element.getAttribute(XSDConstants.SUBSTITUTIONGROUP_ATTRIBUTE);
+    		}
+    	}
+      return "";
     }