The data type of a column being masked is not supported.

Currently, only string, dates and exact numeric columns can be masked. See known limitations for more info.

How to fix

Remove the column from the configuration. This means that it will not be masked, but the masking step will be able to be run for the other tables/columns.

Problem example:

{
  "tables": [
    {
      "schema": "dbo",
      "name": "Products",
      "columns": [
        {
          "name": "ProductImage",          // VARBINARY column type
          "dataset": "Images"              // Not supported
        },
        {
          "name": "ProductName",
          "dataset": "ProductNames"
        }
      ]
    }
  ]
}

Remove the unsupported column:

{
  "tables": [
    {
      "schema": "dbo",
      "name": "Products",
      "columns": [
        {
          "name": "ProductName",           // Only supported columns remain
          "dataset": "ProductNames"
        }
      ]
    }
  ]
}