Error opening PDF file after downloading from server Flutter - flutter

Question

Hello I have a screen in the app that downloads a PDF file and displays the download progress in percent. After downloading, the file is opened using the package of pdf_render: ^ 1.0.10. Sometimes it opens and displays the PDF file and sometimes it does not open the file and I have a blank screen. I have no fault in the console and I do not know what the fault is. Thank you
Flutter App :
class Web_view_vehicle extends StatefulWidget {
var choice ;
var name_vehicle;
Web_view_vehicle({ required this.choice , this.name_vehicle}) : super();
#override
_Web_view_vehicleState createState() => _Web_view_vehicleState();
}
class _Web_view_vehicleState extends State<Web_view_vehicle> {
bool downloading = false;
String progressString = "";
String path = '';
late List data ;
Future<String> get _localPath async {
final directory = await getApplicationDocumentsDirectory();
return directory.path;
}
Future<File> get _localFile async {
final path = await _localPath;
return File('$path/teste.pdf');
}
Future<File> writeCounter(Uint8List stream) async {
final file = await _localFile;
// Write the file
return file.writeAsBytes(stream);
}
Future<Uint8List> fetchPost() async {
Dio dio = Dio();
var response = await dio.get(widget.choice,
onReceiveProgress: (rec, total) {
print("Rec: $rec , Total: $total");
if(!mounted)return;
setState(() {
downloading = true;
progressString = ((rec / total) * 100).toStringAsFixed(0) + "%";
});
},options: Options(responseType: ResponseType.bytes));
final responseJson = response.data;
if (!mounted) {
}
setState(() {
downloading = false;
progressString = "Completed";
});
print("Download completed");
return responseJson;
}
loadPdf() async {
writeCounter((await fetchPost()));
path = (await _localFile).path;
if (!mounted) return;
setState(() {});
}
#override
void initState() {
super.initState();
loadPdf();
}
#override
Widget build(BuildContext context) {
Color? bgColor = Colors.grey[300];
return Scaffold(
backgroundColor: bgColor,
appBar: AppBar(
leading: Padding(
padding: const EdgeInsets.fromLTRB(5.0 , 0.0 , 0.0 , 0.0),
child: new IconButton(
icon: new Icon(Icons.arrow_back),
onPressed: (){Navigator.pop(context,true);}
),
),
title: Text('מדריך לרכב ${widget.name_vehicle}',textAlign: TextAlign.center,textDirection: TextDirection.rtl,),
backgroundColor: Colors.red[400],
centerTitle: true,
actions: <Widget>[
],
),
body:
(path.length > 5)?
PdfViewer.openFile(path,
):
Center(child: Column(crossAxisAlignment: CrossAxisAlignment.center,mainAxisAlignment: MainAxisAlignment.center,mainAxisSize: MainAxisSize.max,
children: [
CircularProgressIndicator(),
Text('טוען מדריך ${progressString}',textDirection: TextDirection.rtl,textAlign: TextAlign.center,)
],
))
);
}
}