Unsupported operation.
If you received this error after submitting an inventory file, then you supplied a value other than "Update" or "Delete" in the update-delete column. Please resubmit with one of the two valid values.
If you received this error after posting a data feed, then you supplied an OperationType value other than "Update" or "Delete" in your XML envelope. Please repost your document with one of the two valid values.