?? appears in articles and WYSIWYG hack

When I edit my article, the text looks exactly like I want it to look. Also, in the preview below, it looks correct. However, when I publish and view the article, it has ?? inserted in various spots. I examined the post in the wp_posts table and the ?? are indeed in the data.
Any ideas on how they got there? I’ve found I can go edit the article, remove what appears to be a space where the published article shows the ?? , add a space back, save the article, and the ?? is gone. Obviously not a good solution!
I’m using the WYSIWYG hack … https://mudbomb.com/archives/category/software/
The test server I’m working on is here.