Try to remve the curly braces in the toolbar component template: can.view('toolbar-template', {}) will be template: can.view('toolbar-template').
update:
Make require on both AppControl and toolbar component in the main file, you did it like AppControl depend on Component those are independent of each other, in th app 'client mail app' I need appControl just to render the template that contains the custom tag (I need it also to make more then one app)
Mohamed Cherif BOUCHELAGHEM
Mohamed Cherif BOUCHELAGHEM