title: Nuget install of of Entity Framework Core SQL Server in VS for OSX causing build errors
body: <p>I am having an issue when installing <code>Entity Framework Core MSSQL</code> in Visual Studio 2017 for OSX.</p>
  
  <p>I run the below command and the package install correctly, but a few seconds later I get red (build?) errors showing up in all <code>cs</code> files.</p>
  
  <p>What can I do to clear these errors?</p>
  
  <p><code>dotnet add core-udemy package Microsoft.EntityFrameworkCore.SqlServer</code></p>
  
  <p>Output</p>
  
  <pre><code> ~/Projects/core-udemy  ⑂ master +    
  dotnet add core-udemy package Microsoft.EntityFrameworkCore.SqlServer
    Writing /var/folders/fw/_y4_qxxd2ls2lh_dmwrdlp000000gn/T/tmpO0Tl4b.tmp
  info : Adding PackageReference for package 'Microsoft.EntityFrameworkCore.SqlServer' into project '/Users/richardcurteis/Projects/core-udemy/core-udemy/core-udemy.csproj'.
  log  : Restoring packages for /Users/richardcurteis/Projects/core-udemy/core-udemy/core-udemy.csproj...
  info :   CACHE https://api.nuget.org/v3-flatcontainer/microsoft.entityframeworkcore.sqlserver/index.json
  warn : Detected package version outside of dependency constraint: Microsoft.AspNetCore.App 2.1.1 requires Microsoft.EntityFrameworkCore.SqlServer (&gt;= 2.1.1 &amp;&amp; &lt; 2.2.0) but version Microsoft.EntityFrameworkCore.SqlServer 2.2.3 was resolved.
  error: Version conflict detected for Microsoft.EntityFrameworkCore. Install/reference Microsoft.EntityFrameworkCore 2.2.3 directly to project core-udemy to resolve this issue. 
  error:  core-udemy -&gt; Microsoft.EntityFrameworkCore.SqlServer 2.2.3 -&gt; Microsoft.EntityFrameworkCore.Relational 2.2.3 -&gt; Microsoft.EntityFrameworkCore (&gt;= 2.2.3) 
  error:  core-udemy -&gt; Microsoft.AspNetCore.App 2.1.1 -&gt; Microsoft.EntityFrameworkCore (&gt;= 2.1.1 &amp;&amp; &lt; 2.2.0).
  info : Package 'Microsoft.EntityFrameworkCore.SqlServer' is compatible with all the specified frameworks in project '/Users/richardcurteis/Projects/core-udemy/core-udemy/core-udemy.csproj'.
  info : PackageReference for package 'Microsoft.EntityFrameworkCore.SqlServer' version '2.2.3' added to file '/Users/richardcurteis/Projects/core-udemy/core-udemy/core-udemy.csproj'.
  info : Committing restore...
  log  : Generating MSBuild file /Users/richardcurteis/Projects/core-udemy/core-udemy/obj/core-udemy.csproj.nuget.g.props.
  info : Writing lock file to disk. Path: /Users/richardcurteis/Projects/core-udemy/core-udemy/obj/project.assets.json
  log  : Restore failed in 1.83 sec for /Users/richardcurteis/Projects/core-udemy/core-udemy/core-udemy.csproj.
  </code></pre>
  
  <p>My code then displays this on all class declarations...</p>
  
  <pre><code>Error: The type or namespace 'IConfiguration could not be found (are you missing a using directive or an assembly reference?)'
  
  Error: Predefined type 'System.Object' is not defined or imported
  
  Error: Predefined type 'System.Void' is not defined or imported
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/mWpqO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mWpqO.png" alt="enter image description here"></a></p>
  
  <p>And </p>
  
  <p><a href="https://i.stack.imgur.com/P6WLw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/P6WLw.png" alt="enter image description here"></a></p>