Failed opening required 'includes/ckeditor.user.inc'

I've never been able to reproduce this :( but I have different setup PHP/5.5/Linux
This troublesome line was introduced in 2011, so it has been in 7.x-1.13 as well: #1116516: CKeditor + Profile2 = Call to undefined function ckeditor_user_customize_form_validate() on uid=1

Can you comment it out for a while to run update.php?

Hi Xrobak,

Did you ever find the solution to this issue?

Regards,

Joe

Hey Guys, I get this error almost every time I upgrade Drupal core, and again I just got it after going from 7.28 to 7.29. In the past, I've found the problem to be caused by a page cache that maintains reference to the old server location. For example, I had been running out of the following location on my server:

/var/www/drupal-7.28

(with a symlink to that directory). Now I have installed the latest version of Drupal at

/var/www/drupal-7.29

If I leave the ckeditor source in /var/www/drupal-7.28, everything works, but simply removing the ckeditor module from 7.28 results in the error message: "Fatal error: require_once() [function.require]: Failed opening required 'includes/ckeditor.user.inc' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/drupal-7.28/sites/all/modules/ckeditor/ckeditor.module on line 48"

Note that the error mesage includes reference to my drupal-7.28 directory even though I am running everything else out of drupal-7.29. Clearly something is being cached that is maintaining an absolute path reference to the old installation.

As I said above, normally simply doing a full flushing all Drupal caches solves the problem, but currently it is not. I've flushed the caches (using admin menu & using the "cache pages" button on the development/performance page, but I still get the error if ckeditor does not exist in the 7.28 directory.

For me, this is completely repeatable when upgrading between all Drupal versions. Hopefully this detail helps figure out where this absolute path is maintained in whatever cache is being used.

I should add that searching the web does bring up several other references to the problem (without solutions) when upgrading Drupal, including this reference right here on drupal.org: https://www.drupal.org/node/1539688

I switch to module_load_include() to avoid this error, which I think it relates to PHP opcode cache. I also remove the same call in ckeditor_form_user_profile_form_alter() because it is already included globally. Ideally, we should not load it like that, but it's another issue.