title: Error CS0234: The type or namespace name 'Azure' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?) in TFS build
body: <p>I have updated our <strong>ASP.NET Web API</strong> solution to include the <strong>Microsoft.Azure.NotificationHubs</strong> Nuget package as I want to be able to send push notifications to our mobile clients. I have written a new controller that does this. Everything works fine.</p>
  
  <p>When I check-in the code changes to our on-premise TFS build server I am getting the error:</p>
  
  <p><strong>Error CS0234: The type or namespace name 'Azure' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)</strong></p>
  
  <p>I have updated the build server to the latest VS2017 build tools but am still getting the error. I can't determine if this is an <strong>MSBUILD</strong> or <strong>VS</strong> error. </p>
  
  <p>I am using Visual Studio 2017 15.9.4. The project uses .NET Framework 4.6.1. </p>
  
  <p><strong>UPDATE</strong>
  After some further investigation I can see that the TFS build server is NOT restoring the Nuget package for <strong>Microsoft.Azure.NotificationHubs</strong> but restores all the other Nuget packages. So the problem seems to be due to the Nuget package not being restored during the build</p>
  
  <p>Here is a screenshot showing that the <em>package.config</em> correctly references the nuget package. But for some reason this nuget package is NOT getting restored during the build. </p>
  
  <p><a href="https://i.stack.imgur.com/SSHY4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SSHY4.png" alt="enter image description here"></a></p>