'message not well formed' error

I am getting the following error message:

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "invalid",
      "details": {
        "coding": [
          {
            "system": "https://fhir.nhs.uk/ValueSet/Spine-ErrorOrWarningCode-1",
            "code": "MESSAGE_NOT_WELL_FORMED",
            "display": "Message not well formed"
          }
        ]
      },
      "diagnostics": "Request body could not be parsed (content[0].extension: Field required. See ValueSet: https://fhir.nhs.uk/England/CodeSystem/England-NRLContentStability)",
      "expression": [
        "content[0].extension"
      ]
    },
    {
      "severity": "error",
      "code": "invalid",
      "details": {
        "coding": [
          {
            "system": "https://fhir.nhs.uk/ValueSet/Spine-ErrorOrWarningCode-1",
            "code": "MESSAGE_NOT_WELL_FORMED",
            "display": "Message not well formed"
          }
        ]
      },
      "diagnostics": "Request body could not be parsed (content[0].format.display: Input should be 'Contact details (HTTP Unsecured)' or 'Unstructured Document'. See ValueSet: https://fhir.nhs.uk/England/CodeSystem/England-NRLFormatCode)",
      "expression": [
        "content[0].format.display"
      ]
    }
  ]
}

How do I resolve this?

We’ve added validation around the values in the document to make sure the data is consistent with our FHIR valuesets.

This error states that the content.format.display value isn’t valid (this may be due to the casing of the word document i.e. “Unstructured Document” vs “Unstructured document”.

This error also states you need to add the content stability extension. So, you need to indicate via the “content stability” extension whether it’s static or dynamic - i.e. whether the content at the URL provided changes or not.