FormBuilder - There is a configuration left for already removed form field or form components with t

Could I assume that as no identifiers were listed, that it was the first part that was true: There is a configuration left for already removed form field

What does this error mean?

Define what you mean by the "nny new forms built are now being lost"? Does the form throw an error or is the form totally removed from the system?

The form builder engine uses the page builder engine in the background. So you need to have widget identifiers in place. If you change those identifier names, it will cause a lot of problems if you already have forms built.

The form builder displays that error for forms that prior to deployment were displaying fine in the form builder. The form is still there in the database with (for example) the markup below.

Do you know under what circumstances that error is displayed, or do you know what it might mean?

    {
  "editableAreas": [
    {
      "identifier": "DefaultFormBuilderArea",
      "sections": [
        {
          "identifier": "00000000-0000-0000-0000-000000000000",
          "type": "Kentico.DefaultSection",
          "zones": [
            {
              "identifier": "21d4e2af-1992-4534-b90e-992d0f0bf032",
              "formComponents": [
                {
                  "identifier": "37aacf37-03d1-4bac-b135-10696a9e48a6"
                }
              ]
            }
          ],
          "properties": null
        }
      ]
    }
  ]
}

What does your code look like when you started developing form components or form sections?

Sorry, could you explain further what you're asking?

Are you writing code for the form builder? Creating form sections? Did you modify your startup.cs file at all?

Yes, possibly, all of the above! This is a legacy site, and there are custom fields and sections. However none of existing forms suffer from this issue, only new forms. I also don't have a startup.cs file.

If I can just understand what the error means, I have a chance to fix it.

Anyone have the code and could tell me what the exact cause of this error is?