Have been researching endlessly and trying different methods for fixing the vanished Visual Editor problem some of our clients are experiencing since updating to 3.9.1.
I've noticed a heck of a lot of discussion on this problem: http://wordpress.org/tags/visual-editor
- the browsers that you are experiencing the problem in: Firefox 29.0.1, Internet Explorer 11.0.9*, other browsers not yet tested
- whether SCRIPT_DEBUG fixed the error or not: No
"Deprecated TinyMCE API call: <target>.onNodeChange.add(..)" plugin.min.js:1
- the location of the error - both the file name and the line number: .../wp-includes/js/tinymce/plugins/compat3x/plugin.min.js?ver=4021-20140423
- the context of the error - including the whole error stack will help developers: [codeblock snipped by moderator. Please use Pastebin for code blocks over ten (10) lines and post the link here.]
We've tried everything from the concatenated fix from here: http://www.wpbeginner.com/wp-tutorials/how-to-fix-white-text-and-missing-buttons-in-wordpress-visual-editor/, to deactivating plug-ins, and so on.
Note that for the theme we are using the Turbo Editor (theme is Ariele by DXThemes, who are no longer supporting their WP themes it appears --- it has been more than a year since they have answered any support queries for it, even though it is a commercial theme).
If someone could please help us that would be greatly appreciated.