Message Type: Integration-related - Dynamics 365 Business Central.

Cause: The integration does not allow more than one preliminary posting per invoice ID.

The invoice was restarted without first being archived.

Action:

1. Cancel the invoice without reopening it.
2. Reopen the invoice from the archive (e.g., use the search function to find the canceled invoice and reopen it).
3. Change the invoice number.

If this does not resolve the issue, please contact us at the MediusGo Customer Center directly via the support button on the invoice or through the customer portal.