Hi, I’m setting up a site with WordPress 3.7.1.
I was using the Duena theme (http://wordpress.org/themes/duena) but I started to notice problems with the TinyMCE inner editor options window displaying a 404 error page. I was using WP Easy Columns; click on the button in the editor and up pops a 404 error page and not the options for WP Easy Columns.
I have now turned off all plugins and moved to the official WordPress 2012 theme but I still have the same problem. Click on the help button in the editor and up pops the inner editor window and showing a 404 error page. Any ideas anyone? Thanks.