title: Xamarin.iOS build error MSB4096: "ReferenceCopyLocalPaths" does not define a value for metadata "ResolvedFrom"
body: <p>After updating Visual Studio 2017 (including Xamarin) I get an error on several Nuget packages like:</p>
  
  <p>...\MSBuild\Xamarin\Xamarin.Apple.Sdk.targets(29,5): error MSB4096: The item "....nuget\packages\HockeySDK.Xamarin\4.1.3\lib\Xamarin.iOS10\HockeySDK.dll" in item list "ReferenceCopyLocalPaths" does not define a value for metadata "ResolvedFrom". In order to use this metadata, either qualify it by specifying %(ReferenceCopyLocalPaths.ResolvedFrom), or ensure that all items in this list define a value for this metadata.</p>
  
  <p>The error only occurs when building for Xamarin.iOS. Building for Android works fine.</p>
  
  <p>Does anybody know how to fix this?</p>