winrt - System.UnauthorizedAccessException - windows-8

Question

I'm trying to write and read to local storage for Win8. Using a helper I am able to successfully write to my machine, but reading the .xml file gives me a: System.UnauthorizedAccessException occurred in mscorlib.dll error
I created a codepaste so you can see my code.
http://codepaste.net/k9mht5
The code is failing here:
public async static Task<object> LoadData(string path, System.Type type)
{
var _Folder = Windows.Storage.ApplicationData.Current.LocalFolder;
try
{
var _File = await Folder.GetFileAsync(path);
using (IInputStream inStream = await _File.OpenSequentialReadAsync())
{
// Deserialize the Session State
XmlSerializer x = new XmlSerializer(type);
return x.Deserialize(inStream.AsStreamForRead());
}
}
catch (Exception ex)
{
MessageDialog dialog = new MessageDialog(ex.Message.ToString());
dialog.ShowAsync();
return null;
}
}
Specifically on this line:
using (IInputStream inStream = await _File.OpenSequentialReadAsync())
If you have any ideas on what I am doing incorrectly it would help me out a lot.
I am doing this in Release Preview. If there is any other system information I need to give, please let me know.

Answer 1

Ok, here is what I've noticed. In file vehicleViewModel.cs you call SaveList(); and GetList(); one after another. Both of these methods are declared as async void which means fire and forget. My idea is that while SaveList is trying to save, GetList is trying to read one file at the same time. I tried your code and I got the same error too. Try to change SaveList and GetList methods to be async Task and then use await:
await SaveList();
await GetList();
That did the trick for me.

Answer 2

Use the dispatcher it will solve your problem
await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.High, () =>
{
// Your UI update code goes here!
_dialogService.ShowMessage(rdm.ErrorMessage);
});