Can't add sub-wiki from front end of site

I'm having a problem like the person in this post. If I add a wiki in the Add Wiki section of the WP Dashboard, the dashboard says the wiki is added. But if I click "view page," I receive the message in the attached screenshot: "Wiki page you are looking for does not exist. Feel free to create it yourself." This happens if I try to "Create New" from the front end of a wiki, as well.

Now, if I click "save" on that page, it creates the page, but all of my content that I would have added in the previous step will have been deleted. Also, not only has the sub-wiki been created, but an identical main-wiki item has been created.

I want anyone to be able to access and add to the wiki, but as it is, the plugin is unusable. Can anyone help with this?