The Database Repository has to be saved before we can proceed to the next step, creating a BO-Layer project.
method 1
Click the Save button 
(Save the current Project or Database Repository) on the Standard Toolbar.
method 2
Right-click the Database Repository in the Project Explorer and choose Save.
method 3
Choose Save Database Repository from the File menu.
Hint:
If you're starting a new project create a new project directory for it and save the Database Repository in this directory