Passing parameter into Task's Action delegate result in exception
Task.Factory.StartNew(() => RenderThumb(UriSource)).ContinueWith((bs) =>
        {....}, TaskScheduler.FromCurrentSynchronizationConext());

private BitmapSource RenderThumb(string uriSource)
    {

        Stream imageStream = File.OpenRead(uriSource);
        ...
        return bitmapSource;
    }

string uriSource = UriSource;

Task.Factory.StartNew(() => RenderThumb(uriSource )).ContinueWith((bs) =>
        {....}, TaskScheduler.FromCurrentSynchronizationConext());

Task.Factory.StartNew(() => RenderThumb(UriSource)).ContinueWith((bs) =>         {....}, TaskScheduler.FromCurrentSynchronizationConext());

Task.Factory.StartNew((s) => RenderThumb(s as String), UriSource).ContinueWith((bs) =>
        {...}, TaskScheduler.FromSynchronizationContext());