flutter Unhandled Exception: XmlParserException: "<" expected at 1:1

Question

The bold code reports the error as follows:

Future<void> a() async {
   ByteData data = await rootBundle.load("assets/e.xlsx");
   var bytes = data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
   var excel = Excel.decodeBytes(bytes);
  }