I made a membership but it was glitchy and didn't load (maybe it was while they were updating stuff). I had a couple of mates sign up as test guinea pigs. When it didn't load, I deleted that membership and created a new one which now is working fine. Now I would like to manually add my mates to the new membership to test, but it says that that email is already taken and can't be used to add a new member to the new membership... Which makes me wonder... how would you add the same person with the same email address to multiple memberships? And how can I manually add people to a membership, even if their email was in the system once (for a deleted membership)?