Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/dao/hibernate/McUsrAttemptDAO.java
===================================================================
diff -u -r45dc9d53a03937ef25d6a8fa6c383c046f5df9f3 -r3fec05d7118aa084eb47e46dddba34b472ff775d
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/dao/hibernate/McUsrAttemptDAO.java	(.../McUsrAttemptDAO.java)	(revision 45dc9d53a03937ef25d6a8fa6c383c046f5df9f3)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/dao/hibernate/McUsrAttemptDAO.java	(.../McUsrAttemptDAO.java)	(revision 3fec05d7118aa084eb47e46dddba34b472ff775d)
@@ -66,7 +66,7 @@
     
     @Override
     public void saveMcUsrAttempt(McUsrAttempt mcUsrAttempt) {
-	this.getHibernateTemplate().save(mcUsrAttempt);
+	this.getHibernateTemplate().saveOrUpdate(mcUsrAttempt);
     }
 
     @Override
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/web/McLearningAction.java
===================================================================
diff -u -rc369c0326857e08851d03a29d39d4337091f5253 -r3fec05d7118aa084eb47e46dddba34b472ff775d
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/web/McLearningAction.java	(.../McLearningAction.java)	(revision c369c0326857e08851d03a29d39d4337091f5253)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/web/McLearningAction.java	(.../McLearningAction.java)	(revision 3fec05d7118aa084eb47e46dddba34b472ff775d)
@@ -29,6 +29,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
+import java.util.regex.Pattern;
 
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
@@ -64,7 +65,10 @@
 import org.lamsfoundation.lams.web.session.SessionManager;
 import org.lamsfoundation.lams.web.util.AttributeNames;
 import org.lamsfoundation.lams.web.util.SessionMap;
+import org.springframework.dao.DataIntegrityViolationException;
 
+import com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException;
+
 /**
  * @author Ozgur Demirtas
  */
@@ -326,7 +330,7 @@
 	mcGeneralLearnerFlowDTO.setUserOverPassMark(new Boolean(passed).toString());
 	mcGeneralLearnerFlowDTO.setPassMarkApplicable(new Boolean(mcContent.getPassMark() != null).toString());
 
-	mcService.saveUserAttempt(mcQueUsr, selectedQuestionAndCandidateAnswersDTO);
+	McLearningAction.saveUserAttempt(mcQueUsr, selectedQuestionAndCandidateAnswersDTO);
 
 	Integer numberOfAttempts = mcQueUsr.getNumberOfAttempts() + 1;
 	mcQueUsr.setNumberOfAttempts(numberOfAttempts);
@@ -393,7 +397,7 @@
 	//save user attempt
 	List<McLearnerAnswersDTO> selectedQuestionAndCandidateAnswersDTO = buildSelectedQuestionAndCandidateAnswersDTO(
 		learnerInput, new McTempDataHolderDTO(), mcContent);
-	mcService.saveUserAttempt(user, selectedQuestionAndCandidateAnswersDTO);
+	McLearningAction.saveUserAttempt(user, selectedQuestionAndCandidateAnswersDTO);
 
 	McQueUsr mcQueUsr = getCurrentUser(toolSessionID);
 	List<McLearnerAnswersDTO> learnerAnswersDTOList = mcService.buildLearnerAnswersDTOList(mcContent, mcQueUsr);
@@ -725,11 +729,36 @@
 	
 	List<McLearnerAnswersDTO> selectedQuestionAndCandidateAnswersDTO = buildSelectedQuestionAndCandidateAnswersDTO(
 		learnerInput, new McTempDataHolderDTO(), mcContent);
-	mcService.saveUserAttempt(user, selectedQuestionAndCandidateAnswersDTO);
+	McLearningAction.saveUserAttempt(user, selectedQuestionAndCandidateAnswersDTO);
 	
 	return null;
     }
     
+    /**
+     * Makes a call to mcService.saveUserAttempt(). This method is designed purely for exception handling purposes. It
+     * needs to be performed inside Action class as otherwise Hibernate tries to flush the session which leads to another exception.
+     */
+    private static void saveUserAttempt(McQueUsr user, List<McLearnerAnswersDTO> selectedQuestionAndCandidateAnswersDTO) {
+	try {
+	    mcService.saveUserAttempt(user, selectedQuestionAndCandidateAnswersDTO);
+
+	} catch (DataIntegrityViolationException e) {
+
+	    // log DB exceptions occurred due to creating non-unique McUsrAttempt. And propagate all the other exceptions
+	    if (e.getRootCause() instanceof MySQLIntegrityConstraintViolationException) {
+		String rootCauseMessage = e.getRootCause().getMessage();
+		
+		Pattern pattern = Pattern.compile("Duplicate entry.*attempt_unique_index");
+		if ((rootCauseMessage != null) && pattern.matcher(rootCauseMessage).find()) {
+		    logger.error("Prevented creation of McUsrAttempt which was not unique for user and question: " + rootCauseMessage);
+		    return;
+		}
+	    }
+	    
+	    throw e;
+	}
+    }
+    
     private static List<String> parseLearnerAnswers(McLearningForm mcLearningForm, HttpServletRequest request) {
 	String httpSessionID = mcLearningForm.getHttpSessionID();
 	SessionMap<String, Object> sessionMap = (SessionMap) request.getSession().getAttribute(httpSessionID);