> ## Documentation Index
> Fetch the complete documentation index at: https://docs.guile.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Invalid Appointment Opening Offer

> The regular opening offer is invalid or was changed

## Cause

The supplied regular opening offer failed tamper validation, so the server cannot trust the booking details it carries. The appointment was not created.

## Fix

Discard the value, list openings again, and create the appointment with the unmodified `offerId` from the new response.

## Retry safety

Not retryable until the request carries an unmodified opening offer.

## Raised by

This operation can return this problem:

* [Create an appointment](/api-reference/appointments/create-an-appointment)

## Example

```json theme={null}
{
  "type": "https://docs.guile.app/problems/invalidAppointmentOpeningOffer",
  "title": "Invalid Appointment Opening Offer",
  "status": 422,
  "detail": "The regular opening offer failed tamper validation."
}
```