Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java
===================================================================
diff -u -r5c770157545dea3dbc72e22a1dd1107c56cf22eb -r9c5964cc6b8152e9ddb6651e900b7b74f0a4e110
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java	(.../AssessmentServiceImpl.java)	(revision 5c770157545dea3dbc72e22a1dd1107c56cf22eb)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java	(.../AssessmentServiceImpl.java)	(revision 9c5964cc6b8152e9ddb6651e900b7b74f0a4e110)
@@ -902,9 +902,18 @@
 
     @Override
     public AssessmentResult getLastFinishedAssessmentResultNotFromChache(Long assessmentUid, Long userId) {
-	AssessmentResult result = getLastFinishedAssessmentResult(assessmentUid, userId);
-	assessmentQuestionDao.evict(result);
-	return getLastFinishedAssessmentResult(assessmentUid, userId);
+	AssessmentResult finishedResult = getLastFinishedAssessmentResult(assessmentUid, userId);
+	
+	//in case user played tricks with accessing Assessment using two tabs, finishedResult can be null and thus we need to request the last *not finished* result
+	if (finishedResult == null) {
+	    AssessmentResult notFinishedResult = getLastAssessmentResult(assessmentUid, userId);
+	    assessmentQuestionDao.evict(notFinishedResult);
+	    return getLastAssessmentResult(assessmentUid, userId);
+	    
+	} else {
+	    assessmentQuestionDao.evict(finishedResult);
+	    return getLastFinishedAssessmentResult(assessmentUid, userId);
+	}
     }
 
     @Override
Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/web/action/LearningAction.java
===================================================================
diff -u -rfeb6062a5128a445b1fa0095b8c9d6cf232af90f -r9c5964cc6b8152e9ddb6651e900b7b74f0a4e110
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/web/action/LearningAction.java	(.../LearningAction.java)	(revision feb6062a5128a445b1fa0095b8c9d6cf232af90f)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/web/action/LearningAction.java	(.../LearningAction.java)	(revision 9c5964cc6b8152e9ddb6651e900b7b74f0a4e110)
@@ -1131,7 +1131,7 @@
 		}
 	    }
 
-	    Date timeTaken = new Date(result.getFinishDate().getTime() - result.getStartDate().getTime());
+	    Date timeTaken = result.getFinishDate() == null ? new Date(0) : new Date(result.getFinishDate().getTime() - result.getStartDate().getTime());
 	    result.setTimeTaken(timeTaken);
 	    if (assessment.isAllowOverallFeedbackAfterQuestion()) {
 		int percentageCorrectAnswers = (int) (result.getGrade() * 100 / result.getMaximumGrade());