Oracle Designer post install steps

Oracle XE Made Easy(Database 10g Express)

After installing the Designer software, go to \repadm61\UTL\ckrorole.sql. First look at the file, it will tell you what privileges/roles that the repository owner will need. Run the script as sys. Create the repository owner user, and grant the appropriate privileges/roles to the repository owner. Now you can start the RAU to create the designer repository.
dodatkowo:
grant execute on sys.dbms_rls to <repo_user>;
grant select on sys.v_$parameter to <repo_user>;

by Oracle Desinger: How to install and login