Why is my membership plugin not showing in my wordpress side menu?

I have been having problems with this site all day long. First, I had to reinstall the entire theme, because for some reason, the stylesheet wasn't being found and the whole site broke. My most recent issue is that the membership plugin is not showing up in the side menu of my wordpress. I disabled every single plugin, deleted the membership plugin, deleted all of the database tables, and then reinstalled and activation the membership plugin and it is not showing up. I could sure use some help on this one.

UPDATE: I also tried reinstalling wordpress, deleting all of the pages that the membership plugin creates, in addition to deleting the database tables, and nothing seems to be working. After all of that, when I try to reinstall the membership plugin, the database tables do not get created, the pages do not get created, and the membership menu does not show up in the left wordpress menu.

This is a very strange issue.

UPDATE 2:

I tried installing the membership plugin on a pretty fresh install of wordpress for a completely different site, and the membership menu also did not show up for this website.

Is the plugin broken?

Please let me know if any of you have any ideas.

Thanks!