Fatal error after update to 1.2.1

After updating the plugin from 1.2.0 to 1.2.1 a fatal error occurs:

PHP Fatal error: Uncaught Error: Call to undefined function as_next_scheduled_action() in /…/wp-content/plugins/pdf-generator-for-wp/common/class-pdf-generator-for-wp-common.php:591
Stack trace:

0 /…/wp-includes/class-wp-hook.php(308): Pdf_Generator_For_Wp_Common->wpg_reset_invoice_number_schedular()

1 /…/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()

2 /…/wp-includes/plugin.php(517): WP_Hook->do_action()

3 /…/wp-settings.php(623): do_action()

4 /…/wp-config.php(94): require_once('…')

5 /…/wp-load.php(50): require_once('…')

6 /…/wp-blog-header.php(13): require_once('…')

7 /…/index.php(17): require('…')

8 {main}

thrown in /…/wp-content/plugins/pdf-generator-for-wp/common/class-pdf-generator-for-wp-common.php on line 591

Doing a rollback to 1.2.0 for now.