yet another stupid mistake

e-Knife/src/main/java/eknife/EKnife.java

@@ -199,6 +199,7 @@ public class EKnife {
 				System.exit(1);
 			}
 		} catch (IllegalArgumentException e) {
+			SC = null;
 			System.out.println("Error: the slicing criterion could not be found! " + slicingCriterion);
 			System.exit(1);
 		}