diff --git a/src/main/java/org/gcube/portlets/user/dataminermanager/server/SessionUtil.java b/src/main/java/org/gcube/portlets/user/dataminermanager/server/SessionUtil.java
index 73610e5..5457fe1 100644
--- a/src/main/java/org/gcube/portlets/user/dataminermanager/server/SessionUtil.java
+++ b/src/main/java/org/gcube/portlets/user/dataminermanager/server/SessionUtil.java
@@ -60,10 +60,30 @@ public class SessionUtil {
 				scope = pContext.getCurrentScope(httpServletRequest);
 			}
 		
+			if(scope==null||scope.isEmpty()){
+				String error="Error retrieving scope: "+scope;
+				logger.error(error);
+				throw new ServiceException(error);
+			}
+			
 			userName = pContext.getCurrentUser(httpServletRequest)
 					.getUsername();
 			
+			if(userName==null||userName.isEmpty()){
+				String error="Error retrieving username in scope "+scope+": "+userName;
+				logger.error(error);
+				throw new ServiceException(error);
+			}
+			
 			token = pContext.getCurrentUserToken(httpServletRequest);
+			
+			if(token==null||token.isEmpty()){
+				String error="Error retrieving token for "+userName+" in "+scope+": "+token;
+				logger.error(error);
+				throw new ServiceException(error);
+			}
+			
+			
 			String name = pContext.getCurrentUser(httpServletRequest)
 					.getFirstName();
 			String lastName = pContext.getCurrentUser(httpServletRequest)