“Legacy cron processing for plugins (core\task\legacy_plugin_cron_task)” error when flashcard cron is executed.

PHP Fatal error: Declaration of mod_flashcard\privacy\provider::delete_data_for_all_users_in_context(core_privacy\local\request\deletion_criteria $criteria) must be compatible with core_privacy\local\request\core_user_data_provider::delete_data_for_all_users_in_context(context $context) in http/mod/flashcard/classes/privacy/provider.php on line 28