Notification of maternity leave given before MAT B1 has been issued

What causes this issue?

An employee can only give notice of her intention to take Statutory
Maternity Leave after she has been given a MAT B1 form by a doctor or
midwife. You have entered a notification date that is before the date
that the MAT B1 form was issued.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Enter a notification date that is on or after the issue date of the MAT
B1 form.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.