Invalid Operation outcome

In this example, operation outcome resource is having an invalid error during the validation operation.

{
    "resourceType": "OperationOutcome",
    "id": "333b21f7-a92c-4ec5-987b-62c13e1dbde9",
    "issue":  [
        {
            "severity": "error",
            "code": "invalid",
            "diagnostics": "<Content invalid against the specification or a profile>"
        }
    ]
}