As @wwalc reported at:
There is something wrong with the module (error message at least is wrong). To reproduce, unpack CKEditor in sites/all/libraries and then rename sites/all/libraries into sites/all/_libraries.
The error message that will show up will in admin/config/content/ckeditor will look like this:
The CKEditor component is not installed correctly. Please go to the CKEditor homepage to download the latest version. After that you must extract the files to sites/all/libraries/ckeditor or sites/all/libraries/ckeditor and make sure that the file sites/all/libraries/ckeditor/ckeditor.js or sites/all/libraries/ckeditor/ckeditor.js exist. Refer to the README.txt for more information.
I suppose one of the alternatives should be "sites/all/modules/ckeditor/ckeditor"