diff --git a/src/main/java/org/gcube/common/portal/PortalContext.java b/src/main/java/org/gcube/common/portal/PortalContext.java
index c57e413..a46607f 100644
--- a/src/main/java/org/gcube/common/portal/PortalContext.java
+++ b/src/main/java/org/gcube/common/portal/PortalContext.java
@@ -11,6 +11,8 @@ import java.util.Properties;
 
 import javax.servlet.http.HttpServletRequest;
 
+import org.gcube.common.authorization.client.exceptions.ObjectNotFound;
+import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
 import org.gcube.common.authorization.library.provider.UserInfo;
 import org.gcube.common.scope.api.ScopeProvider;
 import org.gcube.vomanagement.usermanagement.impl.LiferayGroupManager;
@@ -246,7 +248,7 @@ public class PortalContext {
 		}
 		return -1;
 	}
-	
+
 
 	/**
 	 * 
@@ -259,9 +261,18 @@ public class PortalContext {
 		if (groupIdNo != null) {
 			String scope = getCurrentScope(httpServletRequest);
 			String username = getCurrentUser(httpServletRequest).getUsername();
+			String userToken = null;
 			try {
-				return getAuthorizationToken(username, scope);
-			} catch (Exception e) {
+				ScopeProvider.instance.set(scope);
+				userToken = authorizationService().resolveTokenByUserAndContext(username, scope);
+				SecurityTokenProvider.instance.set(userToken);
+			} 
+			catch (ObjectNotFound ex) {
+				userToken = generateAuthorizationToken(username, scope);
+				SecurityTokenProvider.instance.set(userToken);
+				_log.debug("generateAuthorizationToken OK for " + username + " in scope " + scope);
+			}			 
+			catch (Exception e) {
 				_log.error("Error while trying to generate token for user " + username + "in scope " + scope);
 				e.printStackTrace();
 				return null;
@@ -278,20 +289,23 @@ public class PortalContext {
 		}
 		return null;
 	}
-	
+
 	/**
 	 * 
 	 * @param username
 	 * @param scope
 	 * @throws Exception
 	 */
-	private static String getAuthorizationToken(String username, String scope) throws Exception {
-		ScopeProvider.instance.set(scope);
-		_log.debug("calling service token on scope " + scope);
+	private static String generateAuthorizationToken(String username, String scope) {
 		List<String> userRoles = new ArrayList<>();
 		userRoles.add(DEFAULT_ROLE);
-		String token = authorizationService().generateUserToken(new UserInfo(username, userRoles), scope);
-		_log.debug("received token: "+token);
+		String token;
+		try {
+			token = authorizationService().generateUserToken(new UserInfo(username, userRoles), scope);
+		} catch (Exception e) {
+			e.printStackTrace();
+			return null;
+		}
 		return token;
 	}
 	/**
@@ -650,7 +664,7 @@ public class PortalContext {
 			return null;
 		}		
 	}
-	
+
 	/**
 	 * for development purposes only
 	 */
@@ -703,7 +717,7 @@ public class PortalContext {
 			return null;
 		}		
 	}
-	
+
 	/**
 	 * for development purposes only
 	 */
@@ -738,8 +752,8 @@ public class PortalContext {
 		}		
 		return -1L;
 	}
-	
-	
+
+
 	/**
 	 * 
 	 * @return $CATALINA_HOME
@@ -747,7 +761,7 @@ public class PortalContext {
 	private static String getCatalinaHome() {
 		return (System.getenv("CATALINA_HOME").endsWith("/") ? System.getenv("CATALINA_HOME") : System.getenv("CATALINA_HOME")+"/");
 	}
-	
+
 	/**
 	 * 
 	 * @return $GCUBE-DEV-HOME