Basically I have this problem which keeps occuring.
Once a user subscribes, it all works fine. He can cancel/change subscription no problem.
However, once they have changed their subscription once, I cant call swap or cancel without it throwing an error on null
Call to a member function cancelNow() on null Call to a member function Swap() on null
Both mean that $user->subscription($membership_group) = null.
What could be causing this?