Cannot Enable Memberships Plugin

Hello,

I am testing memberships for my site, but when I attempted to activate the plugin it claimed that I did not have permission to do this. This is a clean install of wordpress with a new site that I'm developing with upfront. There is only 1 registered user on my test site (me, the admin). I've attached a screenshot of the page where it prompts me to activate Memberships, and when I click "Enable It" I simply get a message reading "You do not have sufficient permissions to access this page."

Thanks