Membership plugin unable to use default register page for subscription page [Solved]

Well, though it's not highly essential, why can't I see subscriptions on the default registration page (, if I choose it here:

In curiosity, I tried to use all pages which BuddyPress uses. None of the pages work, except the activation page. Then I removed the default registration page from ( from BuddyPress and used it with Membership for registration. Now it shows the subscriptions.