Just in case anyone’s curious, my problem was caused by an old install of BBPress which has been deactivated and deleted for a while. I had spent some time poking around in the database and working on fixing the user roles and capabilities there through phpMyAdmin with no luck. I reset the user roles and capabilities through OptimizeMember, a commercial plugin that came with our theme, but that didn’t solve it. I just tried the plugin User Role Editor to reset all the user roles and capabilities (after doing a database backup just in case) and it worked like a charm. So thankful!
