Shortcode error

Hi there,
I dont know why and how, but i guees i updated your plugin. And now it shows me this error, when i try to register a new account on woocormerce “my-account” page.
Fatal error: Uncaught Error: Call to a member function get_items() on bool in /var/www/vhosts/fastgames.dk/fastgames.dk/wp-content/plugins/yaymail/includes/MailBuilder/Shortcodes.php:233 Stack trace: #0

When i disable your plugin it works again, idk what the error is.

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