CKEditor does not work The ckeditor on my site suddenly stopped working without changing anything.

This is what I tried up to now:


update all other modules and drupal core 
remove ckeditor
clear caches of drupal and browser
download the latest drupal ckeditor module
download the latest ckeditor full version and copy it in ckeditor/ckeditor
copy all to modules/ckeditor
check if ckeditor.config.js is their.
turn module on
check status report -> no error
set permission -> admin -> full html


PROBLEM: ckeditor is not showing nor is its configuration (admin/config/content/ckeditor).

**extra info*
jquery version 1.7
using the default
compression level production
jQuery and jQuery UI CDN none*

Non of the answers found on this site concerning this subject has been of help yet.
I tried using firefox and chrome.

Thanks in advance.
You have done everything I would have done. 

Try a different path to ckeditor library. Install the libraries module and put the ckeditor library under libraries/ckeditor/ckeditor.js.

Try uninstalling the Drupal CKEditor module and go with the WYSIWYG module and see if that helps.

Also, try with different versions of jQuery. Sometimes the newer versions (1.9+) conflict with a lot of modules, though 1.7 which you are using is the sweet spot I have found.

And lastly try with an older version of CKEditor plugin.