Unable to load css files using ['#attached'] or drupal_add_css I'm attempting to attach several css files to a Drupal 7 module. All files have identical read/write/execute and owner permissions. I haven't had trouble with one of the three files but I can't get the other two added (checked the loaded stylesheets in developer tools). Here's what I've tried:

&lt;?php
function usspd_search_main_form($form, $form_state) {
  $form['#attached']['css']['css1'] = '/sites/all/libraries/data_search/bootstrap_tagsinput/bootstrap_tagsinput.css'; //failed
  $form['#attached']['css']['css2'] = '/sites/all/libraries/data_search/tagme/tagme_jquery-ui.css'; //failed
  drupal_add_css('/sites/all/libraries/data_search/bootstrap_tagsinput/bootstrap_tagsinput.css'); //failed
  drupal_add_css('/sites/all/libraries/data_search/tagme/tagme_jquery-ui.css'); //failed

  $form['#attached']['css']['css3'] = drupal_get_path('module', 'usspd_search') . '/theme/usspd_search.css'; //works
  return $form;
}


My best guess is that there's a class conflict and instead of overriding, the attachment just fails. Is there any way to declare priority? Otherwise I'll have to add the css from both files inline.

Additionally, I'm able to call everything fine when added as raw HTML to a basic page. It shouldn't be a pathing issue.

&lt;link rel="stylesheet" href="/sites/all/libraries/data_search/bootstrap_tagsinput/bootstrap_tagsinput.css"&gt;
&lt;link rel="stylesheet" href="/sites/all/libraries/data_search/tagme/tagme_jquery-ui.css"&gt;
The pathing was wrong after all. The preceding "/" was messing things up. Strangely, this was not an issue for javascript attachments. For example:

$form['#attached']['css']['css2'] = '/sites/all/libraries/data_search/tagme/tagme_jquery-ui.css'; //fails
$form['#attached']['js']['js2'] = '/sites/all/libraries/data_search/tagme/tagme_jquery-ui.min.js'; //works
$form['#attached']['css']['css2'] = 'sites/all/libraries/data_search/tagme/tagme_jquery-ui.css'; //works