Index: /trunk/EventBenchCore/src/de/ugoe/cs/eventbench/models/Trie.java
===================================================================
--- /trunk/EventBenchCore/src/de/ugoe/cs/eventbench/models/Trie.java	(revision 315)
+++ /trunk/EventBenchCore/src/de/ugoe/cs/eventbench/models/Trie.java	(revision 316)
@@ -250,5 +250,10 @@
 	 */
 	public List<T> getContextSuffix(List<T> context) {
-		List<T> contextSuffix = new LinkedList<T>(context); // defensive copy
+		List<T> contextSuffix;
+		if( context!=null ) {
+			contextSuffix = new LinkedList<T>(context); // defensive copy
+		} else {
+			contextSuffix = new LinkedList<T>();
+		}
 		boolean suffixFound = false;