Index: lams_common/src/java/org/lamsfoundation/lams/tool/service/LamsCoreToolService.java
===================================================================
diff -u -rbfa7dfb5557d54767b137652b34dd89c13fb1227 -r9bdc7922225fb1533d0a511eaa3d631222326428
--- lams_common/src/java/org/lamsfoundation/lams/tool/service/LamsCoreToolService.java	(.../LamsCoreToolService.java)	(revision bfa7dfb5557d54767b137652b34dd89c13fb1227)
+++ lams_common/src/java/org/lamsfoundation/lams/tool/service/LamsCoreToolService.java	(.../LamsCoreToolService.java)	(revision 9bdc7922225fb1533d0a511eaa3d631222326428)
@@ -710,10 +710,13 @@
 	}
     }
 
+    @Override
     public Long getActivityMaxPossibleMark(long toolActivityId) {
-	ToolActivity toolActivity = (ToolActivity) activityDAO.getActivityByActivityId(toolActivityId,
-		ToolActivity.class);
-	return getActivityMaxPossibleMark(toolActivity);
+	Activity activity = activityDAO.getActivityByActivityId(toolActivityId);
+	if (!activity.isToolActivity()) {
+	    return null;
+	}
+	return getActivityMaxPossibleMark((ToolActivity) activity);
     }
 
     @Override