UWP trying to run background service throwing exception - triggers

Question

I am trying to run background service in UWP application. I am first checking if application has background permission. If yes then I am registering the service for running.
This code was working fine until I updated Visual Studio along with Windows 10 SDK to Creators Update version. Now I can't figure out if this update changes things for registering background service.
using System;
using Windows.ApplicationModel.Background;
using BackgroundService;
using SampleApp.Config;
namespace SampleApp.Background
{
class BackgroundClass
{
LocalConfig LC = new LocalConfig();
public async void RequestBackgroundAccess()
{
var result = await BackgroundExecutionManager.RequestAccessAsync();
switch (result)
{
case BackgroundAccessStatus.AllowedMayUseActiveRealTimeConnectivity:
break;
case BackgroundAccessStatus.AllowedWithAlwaysOnRealTimeConnectivity:
break;
case BackgroundAccessStatus.Denied:
break;
case BackgroundAccessStatus.Unspecified:
break;
}
}
public async void RegisterBackgroundSync()
{
var trigger = new ApplicationTrigger();
var condition = new SystemCondition(SystemConditionType.InternetAvailable);
if (!LC.BackgroundSyncStatusGET())
{
var task = new BackgroundTaskBuilder
{
Name = nameof(BackgroundSync),
CancelOnConditionLoss = true,
TaskEntryPoint = typeof(BackgroundSync).ToString(),
};
task.SetTrigger(trigger);
task.AddCondition(condition);
task.Register();
LC.BackgroundSyncStatusSET(true);
}
await trigger.RequestAsync(); //EXCEPTION HAPPENS AT THIS LINE
}
public void RegisterBackgroundService(uint time)
{
var taskName = "BackgroundService";
foreach (var unregisterTask in BackgroundTaskRegistration.AllTasks)
{
if (unregisterTask.Value.Name == taskName)
{
unregisterTask.Value.Unregister(true);
}
}
if(time != 0)
{
var trigger = new TimeTrigger(time, false);
var condition = new SystemCondition(SystemConditionType.InternetAvailable);
var task = new BackgroundTaskBuilder
{
Name = nameof(BackgroundService),
CancelOnConditionLoss = true,
TaskEntryPoint = typeof(BackgroundService).ToString(),
};
task.SetTrigger(trigger);
task.AddCondition(condition);
task.Register();
}
}
}
}
Now while requesting I am checking if background service is registered keeping issues for re-registration. I am getting following exception
System.Runtime.InteropServices.COMException occurred
HResult=0x80004005
Message=Error HRESULT E_FAIL has been returned from a call to a COM component.
Source=Windows
 
StackTrace:
  
at Windows.ApplicationModel.Background.ApplicationTrigger.RequestAsync()
  
at SampleApp.Background.BackgroundClass.d__2.MoveNext()
Please Help

Answer 1

Had this same problem, was in my Windows 10 Privacy Settings.
System Settings => Privacy Settings
In the left-hand menu choose Background apps.
Check to make sure your app hasn't been blocked from running background tasks.