My site is having a similar problem. We had thought it was a conflict with the database of another plugin, however the first reply from the Simple-Press administrator indicated there was another issue.
https://simple-press.com/support-forum/sp5-general-topics/wordpress-magazine-theme-not-displaying-forum-cannot-post-to-forum/
Did you find a solution? We’ll try that before posting back to the Simple-Press forums.
