title: Magento server migration: errors
body: <p>I want to move a Magento installation to a new server. I did this:</p>
  
  <ul>
  <li>Backup the database in the backend</li>
  <li>Import the database on new server</li>
  <li>Copy all files from old server to new server</li>
  <li>Set correct file permissions</li>
  <li>Update <code>/app/etc/local.xml</code></li>
  <li>Update secure and unsecure base_url in database</li>
  <li>Remove cache and session files</li>
  </ul>
  
  <p>When I visit the webshop on the new server I get a Php error:</p>
  
  <blockquote>
    <p>PHP Fatal error:  require_once():
    Failed opening required
    'processor.php'
    (include_path='/var/www/domains/example.com/public/app/code/local:/var/www/domains/example.com/public/app/code/community:/var/www/domains/example.com/public/app/code/core:/var/www/domains/example.com/public/lib:.:/usr/share/php:/usr/share/pear')
    in
    \x87\x9b\xa1H\x81\xeb\x19\x8b@#\x95\xd8\x13\x7f
    on line 27</p>
  </blockquote>
  
  <p>Or I get a Magento error:</p>
  
  <blockquote>
    <p>a:5:{i:0;s:77:"Invalid backend model specified:
    catalog/attribute_backend_customlayoutupdate";i:1;s:6393:"#0
    /var/www/domains/example.coml/public/app/code/core/Mage/Eav/Model/Entity/Attribute/Abstract.php(338):
    Mage::exception('Mage_Eav', 'Invalid backend...')</p>
  </blockquote>
  
  <p>The administrator backend works, but if I want to edit products I get the PHP error.</p>
  
  <p>How can I fix this without doing a clean install? I'm running Magento 1.4.0.2-beta1 and I migrated successfully before.</p>
  
  <p>(The solution suggested by learnmagento.org doesn't work)</p>