Bulk deleting error

Bulk deleting licenses leads into the following error:

Fatal error: Call to undefined method WPLM_List_Licenses::delete_licences() in /www/htdocs/w01292e4/projekte/coder/wp-content/plugins/software-license-manager/menu/wp-lic-mgr-list-licenses.php on line 94

Here you can see my current licenses. Maybe because of some active licenses? In this case there should be another error message. If not it should be fixed 🙂

https://ww.wp.xz.cn/plugins/software-license-manager/