ezyVet shows a lockdown date error message when you try to unapprove an invoice
The site has financial lockdown enabled
Financial lockdown is an ezyVet feature that a practice manager uses to prevent changes to financial records (for example, invoices).
Temporarily change the financial lockdown settings
Speak to your practice manager and tell them to change the financial lockdown settings. For example, they can temporarily set Fixed Date of the financial lockdown settings to a date that is before the date of the applicable invoice. Then you can unapprove the invoice.
Make a credit note for the applicable invoice
First, speak to your practice manager about the financial lockdown settings. If they cannot change the financial lockdown settings, you can make a credit note for the applicable invoice. For example, if the invoice has a total value of $100, make a credit note for −$100 and approve the credit note.