Thank you Dennis – I have made significant progress!! I fixed the mandatory fields issues and now each child form is successfully submitted immediately after creation, in an Open state. Initial email notifications go out correctly. However, only the notification sent to the first email address in the list contains a link that will stay open when clicked – (it can then be completed and when submitted again goes to a Closed state). I created a hidden “helper” field in the “Form is Opened” behaviour as you suggested earlier, and I have checked that for each of my child forms (open or closed state) the field does contain a value, which should mean that the form stays open when accessed from the notification. Any ideas? I’ve checked everything I can think of.