I'm using REST to transform a Sales Order into an invoice but running into some issues.

POST {Rest_Services_URL}/record/v1/salesOrder/4441804/!transform/invoice

I get the following error:

{
  "type": "<https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.1>",
  "title": "Internal Server Error",
  "status": 500,
  "o:errorDetails": [
    {
      "detail": "An unexpected error occurred. Error ID: ktbqk9dc18ntnv8bv5vgx",
      "o:errorCode": "UNEXPECTED_ERROR"
    }
  ]
}

I have no issues when I transform the SO into an Item Fulfillment, which makes sense, but I'm still getting the same unexpected error when I try to transform into an invoice.

POST {Rest_Services_URL}/record/v1/salesOrder/4441804/!transform/itemfulfillment

Returns 204 No Content

It looks like this should be supported: https://netsuite.custhelp.com/app/answers/detail/a_id/45156