Pro Login Widget php error

I’ve just had an error appear on my sidebar login widget that says:

Warning: call_user_func_array() expects parameter 1 to be a valid callback, class ‘c_ws_plugin__s2member_login_customizations’ does not have a method ‘lost_password_url’ in /home/xxx/public_html/wp-includes/plugin.php on line 199

Screenshot here

What do I need to do to fix this please?

thanks

https://wordpress.org/plugins/s2member/