After our hosting provider has migrated our website to a new server this fatal error occurs when accessing the site:

Fatal error: Cannot redeclare ctools_menu_add_tab() (previously declared in /www/htdocs/mysite/drupal/sites/all/modules/ctools/includes/menu.inc:42) in /www/htdocs/mysite/drupal/sites/all/modules/ckeditor/ctools/includes/menu.inc on line 49

Now the mother of all questions: How can I fix this? :(

We're using Drupal 6 and – although I haven't checked it yet – all files and databases should have been copied correctly by our hosting provider.

1 Answer 1


You have ctools installed twice, in:

  • sites/all/modules/ctools
  • sites/all/modules/ckeditor/ctools

Obviously the second path must have been mistake. If you can acces your page, disable ctools and then remove second instance. If you can't, try to do it using drush. If that fails, too, consider re-migration, this time properly. If all else fails, you may try to simply remove second instance and call update.php to perform some cleanup.

  • Unfortunately the error is on every page. So I guess I have to check out drush. But it's indeed very strange that ctools is inside the CKEditor module. Apr 1, 2014 at 7:11
  • @HaroldL.Brown Someone must have drag'n'dropped it by accident. Happens. Folders are like next to each other.
    – Mołot
    Apr 1, 2014 at 7:12
  • Are folders automatically scanned by Drupal? I'd have thought that they are ignored if not specifically referenced in the database. Apr 1, 2014 at 7:26
  • @HaroldL.Brown but when Drupal finds database inaccurate, like, after migration, it rescans automagically.
    – Mołot
    Apr 1, 2014 at 7:27
  • 2
    Another problem was that Panels doesn't support PHP 5.4. Apr 2, 2014 at 19:36

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