Cause
The validation_token does not match the current review of the operation.
What to do
Validate the operation again and use the new token.
application/problem+json
{
"type": "https://masnet.com/developers/errors/validation_token_mismatch",
"title": "Different review",
"status": 409,
"detail": "...",
"code": "validation_token_mismatch",
"correlation_id": "..."
}