First thing I installed the free version of wiki to see how it worked and also to see if there would be compatibility issues with the membership plugin and also the mingle plugin currently installed on my site.
Everything worked well together. I also could see how the wiki plugin was to behave and created a thread, logging on and off as test members or as visitors to the site, so that I could see how it worked. It worked well, got the pages with the tabs, they all worked. I left a string of comments - worked well. I put the widget in the sidebar and accessed that wiki from each of the test members. At this point the free visitor could read but not post.
I purchased and downloaded the full version. Before I installed it, I removed the free version from the dashboard and from the file manager of my site.
I installed it, and read the directions on how to use it. I configured everything that could be configured and set up and added my first wiki. I installed the widget to the sidebar of my site, as this is where and how I want people to access it. I also marked anyone could have permission. Now, I have basically a post with no ability to comment, no tabs that I saw in the free version.