Unable to integrate text editor into Moodle 2

I have not been able to integrate CkEditor with Moodle 2.9.1+. (I suspect the issue would apply to any text editor, not just CkEditor.) Per the [README instructions][1], I cloned `moodle-ckeditor` from https://github.com/electrolinux/moodle-ckeditor into the `lib/editor` directory of the moodle installation I administer. I renamed the downloaded directory from `moodle-ckeditor` to `ckeditor`. I added this line to `config.php` in the root moodle directory: $CFG->texteditors='ckeditor,tinymce,htmlarea'; When I navigate to Admin > Plugins > Text editors > Manage editors, I only see the original 3 editors: TinyMCS HTML editor, Plain text area, and Atto HTML editor. FWIW, when I experimentally removed `"tinymce,"` from the shown line of `config.php`, it still showed up on the "Manage editors" page. That makes me think that `$CFG->texteditors` is not being used. I do know it is being read, because I get an error on the "Manage editors" page if I put a syntax error into that line. I've appended a console session in case to call attention to or rule out mistakes due to typos, permissions, etc.: [~/public_html]# grep ckeditor config.php $CFG->texteditors='ckeditor,tinymce,htmlarea'; [~/public_html]# ls -l lib/editor total 28 drwxr-xr-x 7 millscso millscso 4096 Jul 23 16:09 ./ drwxr-xr-x 48 millscso millscso 4096 Jul 16 02:16 ../ drwxr-xr-x 9 millscso millscso 4096 Jul 16 02:16 atto/ drwxr-xr-x 5 millscso millscso 4096 Jul 23 16:09 ckeditor/ drwxr-xr-x 7 millscso millscso 4096 Jul 23 15:59 ckeditor-/ -rw-r--r-- 1 millscso millscso 0 Jul 16 02:16 index.html drwxr-xr-x 3 millscso millscso 4096 Jul 16 02:16 textarea/ drwxr-xr-x 9 millscso millscso 4096 Jul 16 02:16 tinymce/ **Update** A few days after reverting the change to `config.php`, "CKEditor HTML editor" began showing up within Admin > Plugins > Text editors > Manage editors. Unfortunately, when I click on Settings [http://mills-cs.org/admin/settings.php?section=editorsettingsckeditor], I get a [Section error][2]. [1]: https://github.com/electrolinux/moodle-ckeditor [2]: https://docs.moodle.org/29/en/error/admin/sectionerror