Async GetAwaiter() throwing an odd exception
<p>Below I have pasted some code. On the first line of the body I call an awaitable call <code>Task&lt;IEnumerable&lt;SkuGcn&gt;&gt; GetSkuGcnList();</code> On the last line, in the <code>mapPromise.GetAwaiter()</code> it throws when getting the result with this exception: </p>

<blockquote>
  <p>An exception of type 'System.IO.FileNotFoundException' occurred in System.Private.CoreLib.ni.dll but was not handled in user code</p>
  
  <p>Additional information: Could not load file or assembly 'System.Runtime.Serialization.Xml, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. The system cannot find the file specified.</p>
</blockquote>

<p>I know my service that the <code>GetSkuGcnList()</code> call is calling to, is being called, because I can set a break point and I break at it when the call is made.  Then the service seems to return.</p>

<p>This code worked just fine with ASP.NET 5 RC1 but now not so good in ASP.Net Core 1.0 Release.</p>

<p>Any help will be greatly appreciated!</p>

<pre><code>        public ProductItemsCacheStore(IItemsProductCacheRepository itemsRepo, IProductAvailabilityPricing proxyGoliathApi,
        IProductItemListRepo itemsListsRepo, IItemPricesCacheRepo itemPricesRepo)
        {
            var mapPromise = proxyGoliathApi.GetSkuGcnList();
            _items = itemsRepo.GetAllProductOrderListForCache();
            _itemsLists = itemsListsRepo.GetItemListsForCache();
            _priceZones = itemPricesRepo.GetAllPriceZonesAndItemPrices();
            MergeProductsWithGcn(_items, mapPromise.GetAwaiter().GetResult());
        }
</code></pre>

<p>My project.json looks like this:</p>

<pre><code>{
  "version": "1.0.0-alpha.1",
  "description": "AvailabilityPricingClient Class Library",
  "authors": [ "irving.lennert" ],
  "packOptions": {
    "tags": [ "" ],
    "projectUrl": "",
    "licenseUrl": ""
  },

  "tooling": {
    "defaultNamespace": "AvailabilityPricingClient"
  },

  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.0",
      "type": "platform"
    },
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
    "Microsoft.Extensions.Configuration.Json": "1.0.0",
    "Microsoft.Extensions.Logging": "1.0.0",
    "Microsoft.Extensions.Logging.Console": "1.0.0",
    "Microsoft.Extensions.Logging.Debug": "1.0.0",
    "Microsoft.AspNet.WebApi.Client": "5.2.3"
  },

  "frameworks": {
    "netcoreapp1.0": {
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ]
    }
  }
}
</code></pre>

<p>The implementation of <code>GetSkuGcnList()</code> is this:</p>

<pre><code>    public async Task&lt;IEnumerable&lt;SkuGcn&gt;&gt; GetSkuGcnList()
    {
        HttpResponseMessage response = _client.GetAsync("/api/skuGcnList").Result;

        if (response.IsSuccessStatusCode)
        {
            var skuGcns = await response.Content.ReadAsAsync&lt;IEnumerable&lt;SkuGcn&gt;&gt;();
            return skuGcns;
        }

        return null;
    }
</code></pre>