Viewpoints Activated but not Displaying

Dear All,
I have installed the basic viewpoints (1.1.0) as described on the website and the tutorials (via drop-in). Upon referencing and activating e.g. the mass viewpoint
I am still unable to add mass annotations or to view the UI elements of the mass VP anywhere in the diagram editor (or elsewhere).
Am I missing some important step?
I observe the same behavior when running a test instance from Capella Studio 1.1.0 for the mass viewpoint (imported as source) and for a custom viewpoint I created.
Thanks a lot in advance for your help!
Best,
Sergio

Sorry for the stupid question, it appears I have figured it out myself:
On the diagram editor, it is necessary to activate the layer corresponding to the viewpoint(s).
Thanks anyway!

Yes indeed!
Hopefully you found the answer by yourselves but thanks for sharing the solution, it could help others.