I created a wiki topic on my site, and it worked great for a while. A couple weeks after creating it and getting several edits, it is now giving a 403 error to any non-admin user who tries to edit it. I as the admin can edit it, but nobody else seems to be able to. Trust levels all look appropriate. Also the message box actually has no error message in it. One of my users got this screenshot.
I did recently upgrade to the most recent version, could that have caused an issue?