C# Blog Reader - 3 - Asynchronous programming

thank you for video. it successfully build  but when i run it show  

An exception of type 'System.Runtime.InteropServices.COMException' occurred in mscorlib.dll but was not handled in user code

Additional information: Error HRESULT E_FAIL has been returned from a call to a COM component.

If there is a handler for this exception, the program may be safely continued.

in this line

  FeedDataSource feedDataSource = (FeedDataSource)App.Current.Resources["feedDataSource"];

@MSPNitesh: I had the same exception till I discovered that I misspelled:

<local:FeedDataSource x:Key="feedDataSource" />

 in app.xaml , correcting it, this exception was no more showed. 

once resolved, I had another exception:

"A first chance exception of type 'System.Exception' occurred in mscorlib.dll

WinRT information: DTD is prohibited."

at line:

SyndicationFeed feed = await client.RetrieveFeedAsync(feedUri);

All web links  do not work , making the code throw  System.Exception in mscorlib.dll
at line:
                SyndicationFeed feed = await client.RetrieveFeedAsync(feedUri);
please update web links due to switch from
http://windowsteamblog.com
to
http://blogs.windows.com

Instead of what in the video and in the complete code :

 Task<FeedData> feed1 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/developers/atom.aspx");
            Task<FeedData> feed2 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/windowsexperience/atom.aspx");
            Task<FeedData> feed3 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/extremewindows/atom.aspx");
            Task<FeedData> feed4 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/business/atom.aspx");
            Task<FeedData> feed5 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/bloggingwindows/atom.aspx");
            Task<FeedData> feed6 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/windowssecurity/atom.aspx");
            Task<FeedData> feed7 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/springboard/atom.aspx");
            Task<FeedData> feed8 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/windowshomeserver/atom.aspx");
            // There is no Atom feed for this blog, so use the RSS feed.
            Task<FeedData> feed9 =
                GetFeedAsync("http://windowsteamblog.com/windows_live/b/windowslive/rss.aspx"); Task<FeedData> feed10 = GetFeedAsync("http://windowsteamblog.com/windows_live/b/developer/atom.aspx");
            Task<FeedData> feed11 =
                GetFeedAsync("http://windowsteamblog.com/ie/b/ie/atom.aspx");
            Task<FeedData> feed12 =
                GetFeedAsync("http://windowsteamblog.com/windows_phone/b/wpdev/atom.aspx");
            Task<FeedData> feed13 =
                GetFeedAsync("http://windowsteamblog.com/windows_phone/b/wmdev/atom.aspx");
            Task<FeedData> feed14 =
                GetFeedAsync("http://windowsteamblog.com/windows_phone/b/windowsphone/atom.aspx");

This should be used as links are working:

Task<FeedData> feed1 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/bloggingwindows/rss.aspx");

Task<FeedData> feed2 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/windowsexperience/rss.aspx");

Task<FeedData> feed3 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/extremewindows/rss.aspx");

Task<FeedData> feed4 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/business/rss.aspx");

Task<FeedData> feed5 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/windowssecurity/rss.aspx");

Task<FeedData> feed6 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/springboard/rss.aspx");

Task<FeedData> feed7 =

                GetFeedAsync(

"http://blogs.windows.com/windows/b/windowshomeserver/rss.aspx");

Task<FeedData> feed8 =

                GetFeedAsync(

"http://blogs.windows.com/windows_live/b/windowslive/rss.aspx");

Task<FeedData> feed9 =

                GetFeedAsync(

"http://blogs.windows.com/windows_live/b/developer/rss.aspx");

Task<FeedData> feed10 =

                GetFeedAsync(

"http://blogs.windows.com/ie/b/ie/rss.aspx");

Task<FeedData> feed11 =

                GetFeedAsync(

"http://blogs.windows.com/skydrive/b/skydrive/rss.aspx");

Task<FeedData> feed12 =

                GetFeedAsync(

"http://blogs.windows.com/windows_phone/b/windowsphone/rss.aspx");

Task<FeedData> feed13 =

                GetFeedAsync(

"http://blogs.windows.com/windows_phone/b/wpdev/rss.aspx");

Task<FeedData> feed14 =

                GetFeedAsync(

"http://blogs.windows.com/windows_phone/b/wmdev/rss.aspx");