Using the translation manager currently leads to the email template used by a notification being unlinked. If you've used the translation manager, you can check on your enabled email notifications that there is a template associated to it. If there isn't, notification are no longer being sent.
We're working on a fix and have disabled the translation manager in the meantime.
If your notifications are being sent right now, the performance isn't affected.
Once this is fixed, we'll work on restoring the email template for the notifications affected.
