I'm trying to make a simple log in/ log out web application with maven and I'm creating the project with the command: " mvn archetype:generate " and choose 341 and it'll be created with the structure below: webapp -----src/main/java -----Referenced Libraries -----Maven Dependencies -----src -----target pom.xml But when I add some dependencies and update the project something weird happening with the structure of the project according to the picture below: webapp -----src/main/java -----Referenced Libraries -----JRE System Library -----src -----target pom.xml and it's not working any more. As you can see the the first one has a Maven dependencies Library but the second one has been changed to JRE System Library. I use mac os lion and eclipse indigo. Anyone how knows why is like that? Tancks