diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/ExpressionServiceImpl.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/ExpressionServiceImpl.java
index c90fde5..662317d 100644
--- a/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/ExpressionServiceImpl.java
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/ExpressionServiceImpl.java
@@ -2,6 +2,7 @@ package org.gcube.portlets.user.td.expressionwidget.server;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.ResourceBundle;
 
 import javax.servlet.http.HttpSession;
 
@@ -26,6 +27,7 @@ import org.gcube.portlets.user.td.expressionwidget.shared.exception.ExpressionPa
 import org.gcube.portlets.user.td.expressionwidget.shared.exception.ExpressionServiceException;
 import org.gcube.portlets.user.td.gwtservice.server.SessionUtil;
 import org.gcube.portlets.user.td.gwtservice.server.TDGWTServiceImpl;
+import org.gcube.portlets.user.td.gwtservice.server.TDGWTServiceMessagesConstants;
 import org.gcube.portlets.user.td.gwtservice.server.trservice.ColumnDataTypeMap;
 import org.gcube.portlets.user.td.gwtservice.shared.exception.TDGWTServiceException;
 import org.gcube.portlets.user.td.gwtservice.shared.rule.AppliedRulesResponseData;
@@ -71,10 +73,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public String startFilterColumn(FilterColumnSession filterColumnSession)
 			throws TDGWTServiceException {
-
+		HttpSession session=null;
 		try {
 			logger.debug("ExpressionService submitColumnFilter");
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			logger.debug("Session: " + session);
 
 			if (filterColumnSession == null) {
@@ -103,6 +105,12 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 
 		} catch (TDGWTServiceException e) {
 			throw e;
+		} catch (SecurityException e) {
+			logger.error(e.getLocalizedMessage());
+			e.printStackTrace();
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));		
 		} catch (Throwable e) {
 			e.printStackTrace();
 			throw new TDGWTServiceException(e.getLocalizedMessage());
@@ -116,10 +124,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 
 	public String startAddColumn(AddColumnSession addColumnSession)
 			throws TDGWTServiceException {
-
+		HttpSession session=null;
 		try {
 			logger.debug("AddColumn");
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			logger.debug("Session: " + session);
 
 			if (addColumnSession == null) {
@@ -153,6 +161,13 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 
 		} catch (TDGWTServiceException e) {
 			throw e;
+		} catch (SecurityException e) {
+			logger.error(e.getLocalizedMessage());
+			e.printStackTrace();
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));	
+		
 		} catch (Throwable e) {
 			e.printStackTrace();
 			throw new TDGWTServiceException(e.getLocalizedMessage());
@@ -168,9 +183,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 			ReplaceColumnByExpressionSession replaceColumnByExpressionSession)
 			throws TDGWTServiceException {
 
+		HttpSession session=null;
 		try {
 			logger.debug("ExpressionService submitReplaceColumnByExpression");
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			logger.debug("Session: " + session);
 
 			if (replaceColumnByExpressionSession == null) {
@@ -215,6 +231,12 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 
 		} catch (TDGWTServiceException e) {
 			throw e;
+		} catch (SecurityException e) {
+			logger.error(e.getLocalizedMessage());
+			e.printStackTrace();
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));	
 		} catch (Throwable e) {
 			e.printStackTrace();
 			throw new TDGWTServiceException(e.getLocalizedMessage());
@@ -228,8 +250,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public ArrayList<RuleDescriptionData> getRules()
 			throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("GetRules()");
@@ -259,7 +282,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
+	
 		} catch (Throwable e) {
 			logger.error("Error in getRules(): " + e.getLocalizedMessage());
 			e.printStackTrace();
@@ -276,8 +302,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public ArrayList<RuleDescriptionData> getRules(RuleScopeType scope)
 			throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("GetRules(): " + scope);
@@ -308,7 +335,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
 		} catch (Throwable e) {
 			logger.error("Error in getRules(): " + e.getLocalizedMessage());
 			e.printStackTrace();
@@ -325,8 +354,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public ArrayList<RuleDescriptionData> getApplicableBaseColumnRules(
 			ColumnData columnData) throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("GetApplicableBaseColumnRules(): " + columnData);
@@ -373,7 +403,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
+	
 		} catch (Throwable e) {
 			logger.error("Error in getApplicableBaseColumnRules(): "
 					+ e.getLocalizedMessage());
@@ -391,8 +424,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public AppliedRulesResponseData getActiveRulesByTabularResourceId(TRId trId)
 			throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("GetAppliedRulesByTabularResourceId(): " + trId);
@@ -429,7 +463,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
+	
 		} catch (Throwable e) {
 			logger.error("Error in getActiveRulesByTabularResourceId(): "
 					+ e.getLocalizedMessage());
@@ -448,8 +485,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	public String saveRule(
 			RuleDescriptionData ruleDescriptionData)
 			throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("SaveRule() :" + ruleDescriptionData);
@@ -502,7 +540,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
+	
 		} catch (Throwable e) {
 			logger.error("Error in save rule: "
 					+ e.getLocalizedMessage());
@@ -521,8 +562,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public void updateColumnRule(RuleDescriptionData ruleDescriptionData)
 			throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("UpdateColumnRule() :" + ruleDescriptionData);
@@ -551,7 +593,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
+	
 		} catch (Throwable e) {
 			logger.error("Error in getRule(): " + e.getLocalizedMessage());
 			e.printStackTrace();
@@ -568,8 +613,9 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 	@Override
 	public void removeRulesById(ArrayList<RuleDescriptionData> rules)
 			throws TDGWTServiceException {
+		HttpSession session=null;
 		try {
-			HttpSession session = this.getThreadLocalRequest().getSession();
+			session = this.getThreadLocalRequest().getSession();
 			ASLSession aslSession = SessionUtil.getAslSession(session);
 
 			logger.debug("RemoveRuleById() :" + rules);
@@ -594,7 +640,10 @@ public class ExpressionServiceImpl extends TDGWTServiceImpl implements
 		} catch (SecurityException e) {
 			logger.error(e.getLocalizedMessage());
 			e.printStackTrace();
-			throw e;
+			ResourceBundle messages = getResourceBundle(session);
+			throw new TDGWTServiceException(
+					messages.getString(TDGWTServiceMessagesConstants.securityExceptionRights));
+	
 		} catch (Throwable e) {
 			logger.error("Error in removeRuleById(): "
 					+ e.getLocalizedMessage());