Possible solution:
Enable the option 'Automatically generate NAW number' under 'Master data Creditors' or 'Master data Debtors' in KING ERP, or manually enter a code when creating an account in Zenvoices.
This message appears when auto-numbering is disabled in KING ERP.
Enable the option 'Automatically generate NAW number' under 'Master data Creditors' or 'Master data Debtors' in KING ERP, or manually enter a code when creating an account in Zenvoices.