Trying to activate the "Double Opt-in" For Download" plugin, but I keep receiving this message:
I am trying to activate the Double Opt In For Download plugin. After successful installation, i have tried to activate the plugin, but continue to get the following message:
Plugin could not be activated because it triggered a fatal error.
Fatal error: Cannot redeclare upgrade_all() (previously declared in /homepages/13/d376116902/htdocs/wordpress-3.3/wordpress-Backup/wp-admin/includes/upgrade.php:331) in /homepages/13/d376116902/htdocs/wordpress-3.3/wordpress-Backup/wp-admin/includes/upgrade.php on line 414