Can't create view using a role
Being able to create a view is not [quite] enough.
The Owner [account] of the finished View must have read privileges on the Tables used by that view.  These privileges cannot be conferred through any Role.
grant read on friends to owner_of_friends_v4 ; 
grant read on clients to owner_of_friends_v4 ; 

Also, why are you working with Common users here (starting &quot;C##&quot;)?
I would only expect to see these in the Container database, not any of the Pluggable ones that live within it (which is where I would expect to see all Application Tables and Data).