access denied error message when try to show two message dia

I'm getting access denied error message when try to show two message dialogs at the same time.

Case: I'm calling two async service call's and showing service error message response to MessageDialog.

In above case, If I don't have internet connection two message dialog throwing same time and getting "Access Denied" error message.

I'm using below code for showing error message:

MessageDialog dialog = new MessageDialog(responseBase.error.Description, responseBase.error.Title);
await dialog.ShowAsync();