BatchMustContainOneFile
Example
{
	"code": "BatchMustContainOneFile",
	"target": "Unknown",
	"details": [
		{
			"code": "BatchMustContainOneFile",
			"number": 206,
			"message": "A batch must contain one input file.",
			"description": "The batch you uploaded had -0- input files.  Batches may have only one input file.",
			"faultCode": "Client",
			"helpLink": "http://developer.avalara.com/avatax/errors/BatchMustContainOneFile",
			"severity": "Error"
		}
	]
}
Explanation

A Batch object is a file that contains a list of objects being created. It must have one file, and that file can have no more than 100,000 rows in it.