How to rebuild the Drupal 7 registry
Drupal 7 registry issues can look like cache problems. If you're not sure that you've cleared all the caches, you can try the different options for clearing cache as suggested by Chris Shattuck's cache clearing instructions page.
The easiest way to ensure that you've cleared all Drupal caches is to use the following Drush command (which is an abbreviated form of
drush cache-clear all):
drush cc all
If, after clearing the cache, you still encounter errors similar to the following, you might need to rebuild the registry:
PHP Fatal error: Class 'EntityAPIControllerExportable' not found in ...sites/all/modules/rules/includes/rules.core.inc on line 11
Rebuilding the registry
The best way to rebuild your registry is to use Drush from the command line. Run the following command in either the
sites/all/[sitename] folder for a site:
drush php-eval "registry_rebuild();"
If Drush is not working properly, you can also try:
For information about
registry_rebuild (a bootstrap function that can help you rebuild your registry), see the function registry_rebuild API documentation.