We'll create fresh WordPress site with Deactivate Visual Editor installed. You have 20 minutes to test the plugin after that site we'll be deleted.
The visual editor is nice when pages and posts are simple, but when you try to add special text such as php code to a page then the visual editor oftentimes has to be deactivated to edit the page. This plug-in allows you to set which posts should not use the visual editor by setting a custom field ‘deactivate_visual_editor’ to true. This allows the visual editor to be deactivated for the given post/page, but remain active for all others.