In order to work with the ARCCORE tools, you need a valid Arctic Core. The Arctic Core contains the actual code that you need to build and the generators and moddefs and stylesheets in order to configure your modules correctly.
The Core version should match the Studio version if the situation is not analysed and that the differences have been assessed.
Then follow the instructions to import the Core project into studio in the User Documentation in MyARCCORE (you must log in to the customer portal to access these documents).
After that make sure that your project refers to the Core project.