Ticket #12752: 12752.diff

wp-admin/includes/plugin.php

@@ -479 +479 @@
                         $output = ob_get_clean();
                         return new WP_Error('unexpected_output', __('The plugin generated unexpected output.'), $output);
                 }
-                do_action( 'activate_plugin', trim( $plugin) );
                 if ( $network_wide ) {
                         $current[$plugin] = time();
                         update_site_option( 'active_sitewide_plugins', $current );