A binary dataset is being used on a column that is set to be masked deterministically. This is not supported.

How to fix

Change the column to be masked non-deterministically, or use a non-binary file dataset to mask it.

Problem example:

{
  "tables": [
    {
      "schema": "dbo",
      "name": "Documents",
      "columns": [
        {
          "name": "FileContent",
          "dataset": "SampleDocuments",    // Binary file dataset
          "deterministic": true            // Not supported with binary data
        }
      ]
    }
  ],
  "datasets": [
    {
      "name": "SampleDocuments",
      "type": "BinaryFile",
      "file": "SampleDocuments.txt"
    }
  ]
}

Option 1 - Use non-deterministic masking:

{
  "tables": [
    {
      "schema": "dbo",
      "name": "Documents",
      "columns": [
        {
          "name": "FileContent",
          "dataset": "SampleDocuments",
          "deterministic": false           // Changed to non-deterministic
        }
      ]
    }
  ],
  "datasets": [
    {
      "name": "SampleDocuments",
      "type": "BinaryFile",
      "file": "SampleDocuments.txt"
    }
  ]
}

Option 2 - Use a text-based dataset:

{
  "tables": [
    {
      "schema": "dbo",
      "name": "Documents",
      "columns": [
        {
          "name": "FileName",              // Mask file name instead
          "dataset": "FileNames",
          "deterministic": true
        }
      ]
    }
  ],
  "datasets": [
    {
      "name": "FileNames",
      "type": "List",
      "values": ["document1.pdf", "report2.pdf", "file3.docx"]
    }
  ]
}