I get this error on the new beta

PHP Warning: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of mail_edit_trans_save(). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file in C:\Inetpub\wwwroot\Drupal\modules\subscriptions\subscriptions_mail.module on line 463 PHP Warning: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of mail_edit_trans_save(). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file in C:\Inetpub\wwwroot\Drupal\modules\subscriptions\subscriptions_mail.module on line 467

Can someone tell me what´s going on?