title: Visual Studio 2017 Professional- Unable to find package at source
body: <p>I was trying to add package through nuget package manager=> package manager console and from Manage Nuget packages from solution directly. I am trying to install <code>Newtonsoft.Json</code> from Package Manager Like this <code>Install-Package Newtonsoft.Json</code> but unable to find from the source i.e </p>
  
  <pre><code> Name: nuget.org
   Source: https://api.nuget.org/v3/index.json
  </code></pre>
  
  <p>This gives me result like this:</p>
  
  <pre><code>PM&gt; Install-Package Newtonsoft.Json
  Install-Package : Unable to find package 'Newtonsoft.Json' at source ''.
  At line:1 char:1
  + Install-Package Newtonsoft.Json
  + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  + CategoryInfo          : NotSpecified: (:) [Install-Package], Exception
  + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand
  
  Time Elapsed: 00:01:30.2571879
  </code></pre>
  
  <p>I think that the <code>source</code> here is blank. May be because of that it is unable to load packages. I have tried to manage the package manager setting but not been able to connect. My package manager setting is like this:
  <a href="https://i.stack.imgur.com/E15GE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/E15GE.png" alt="Package Manager General Setting"></a></p>
  
  <p><a href="https://i.stack.imgur.com/tNQj6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tNQj6.png" alt="Package Source Setting"></a></p>
  
  <p>Despite of having good connection of internet I am not been able to install package. My questions are:</p>
  
  <ol>
  <li>How should I install package? </li>
  <li>What am I doing wrong to install package?</li>
  </ol>