I originally posted this issue yesterday as a part-two of a problem I was having, but since it is now on page two of the forum, I'll split it into a new post.
I can sign up as a test user, the account is created, but no Access Level becomes associated with it as defined in my Subscription Plans panel.
I tried deactivating all my other plugins to see if there was a conflict, but it did not help.
This may be due to a legacy left in my database by another membership plugin I had once tried: s2Member. I followed these instructions ( https://premium.wpmudev.org/forums/topic/membership-replaces-s2member-but ) to remove s2Member codes from my database, but I fear there may still be some residual problems.
What else should I be looking out for?