Webflow Logic HTTP Request POST JSON Error

Hi there,

I am getting this error message back, when I test my HTTP request flow in Webflow:

{
  "error": {
    "type": "INVALID_VALUE_FOR_COLUMN",
    "message": "Value is not an array of record IDs."
  }
}

Strange that it doesn't name the column. Strange that I am not writing any data with reference to other records into reference fields. It's a simple form with text fields, number field, an email field, a phone field and a checkbox.

No matter how I manipulate the form, this message comes up. The request as such is successfull.

Has anyone experienced this?