Answers.Body: <p>Can you ensure that you do not have two copies of the civicrm codebase (irrespective of what you might have renamed it to) under</p>
  
  <p>[MYSITE]/</p>
  
  <p>Most likely the error is caused by php finding two copies of the CRM/Core/ClassLoader.php file</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-05-24T01:55:25.890Z
Answers.LastActivityDate: 2015-05-24T01:55:25.890Z
Answers.UserDisplayName: Donald Lobo
Body: <p>While upgrading from 4.5.8 to 4.6.3 on a Drupal site, the upgrade script stuck and when I refreshed, i got</p>
  
  <pre><code>Fatal error: Cannot redeclare class CRM_Core_ClassLoader in
  [MYSITE]/sites/all/modules/civicrm/CRM/Core/ClassLoader.php on line 36
  </code></pre>
  
  <p>Now I can't even log into the backend of my site.</p>
  
Tags: <drupal><upgrade>
Title: Fatal error while upgrading
ThreadText: # Fatal error while upgrading
  
  (Asked by: username_0 on 2015-05-24)
  
  While upgrading from 4.5.8 to 4.6.3 on a Drupal site, the upgrade script stuck and when I refreshed, i got
  Fatal error: Cannot redeclare class CRM_Core_ClassLoader in
  [MYSITE]/sites/all/modules/civicrm/CRM/Core/ClassLoader.php on line 36
  
  Now I can't even log into the backend of my site.
  
  **Tags:** drupal, upgrade
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2015-05-24. Score: 5 | Accepted answer
  
  Can you ensure that you do not have two copies of the civicrm codebase (irrespective of what you might have renamed it to) under
  
  [MYSITE]/
  
  Most likely the error is caused by php finding two copies of the CRM/Core/ClassLoader.php file
  
  
  ---
  
  