Fatal error: Uncaught Error: Call to a member function isAdmin() on string in /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Model/Design/Package.php:847 Stack trace: #0 /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Model/Design/Package.php(825): Mage_Core_Model_Design_Package->_prepareUrl('../images/link-...') #1 [internal function]: Mage_Core_Model_Design_Package->_cssMergerUrlCallback(Array) #2 /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Model/Design/Package.php(785): preg_replace_callback('/url\\(\\s*(?!dat...', Array, '/* Reset ======...') #3 /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Helper/Data.php(744): Mage_Core_Model_Design_Package->beforeMergeCss('/opt/bitnami/ap...', '/* Reset ======...') #4 /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Model/Design/Package.php(726): Mage_Core_Helper_Data->mergeFiles(Array, '/opt/bitnami/ap...', false, Array, Array) #5 /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Model/Design/Package.php(677): Mage_Core_Model_Design_Package->_mergeFiles in /opt/bitnami/apache2/htdocs/app/code/core/Mage/Core/Model/Design/Package.php on line 847