Protected Content Membership Signup Error and "Pending"

Adding a protected content membership results in an error: "Sorry, your signup request has failed. Try again." When I look for that user in the Members back-end, they are showing as "Pending".

I've been trying to get this plugin to work correctly for a while and it seems like as soon as I think I'm close, something else goes wrong... Really need to get this working ASAP.

I will go ahead and add support access to my site...