Index: lams_learning/src/java/org/lamsfoundation/lams/learning/web/util/ActivityMapping.java
===================================================================
diff -u -r250486f86b66ac04cece0001879c3dc39c96ed98 -r8cbcfc33f24bb5e0359d189ab44c75a4b019458c
--- lams_learning/src/java/org/lamsfoundation/lams/learning/web/util/ActivityMapping.java	(.../ActivityMapping.java)	(revision 250486f86b66ac04cece0001879c3dc39c96ed98)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/web/util/ActivityMapping.java	(.../ActivityMapping.java)	(revision 8cbcfc33f24bb5e0359d189ab44c75a4b019458c)
@@ -222,7 +222,7 @@
             {
                 // display next activity
                 activityURL = this.getActivityURL(progress.getNextActivity());
-                if (progress.getPreviousActivity().isParallelActivity())
+                if (progress.getPreviousActivity() != null && progress.getPreviousActivity().isParallelActivity())
                 {
                     // if previous activity was a parallel activity then we need to
                     // clear frames.