title: core 2.0 and office interop - where is the microsoft.office.core package?
body: <p>In a standard .NET app, 
  I can add the COM objects for Office Core, Word, Excel, and Powerpoint.  Everything works fine.  </p>
  
  <p>The Office core assembly is needed for some commands (for example, powerpoint uses Office.Core.MsoTriState.msoFalse/True commands for some actions, and word uses AutomationSecurity via Office.Core.MsoAutomationSecurity.</p>
  
  <p>The problem is when I am building an asp net core app.  Nuget has the packages for Excel, Word, and Powerpoint,  which will work properly if I don't reference any Office.Core items, but anytime I reference one I get this error:</p>
  
  <p><code>The type 'MsoTriState' is defined in an assembly that is not referenced. You must add a reference to assembly 'office, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'.</code></p>
  
  <p>I've tried manually adding the MSO.DLL to the project, but still get the same error.</p>
  
  <p>I've also tried adding all the COM objects instead of the nuget packages, but I get an error like this on object creation:</p>
  
  <p><code>Could not load file or assembly 'Interop.Microsoft.Office.Interop.Excel, Version=1.8.0.0, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.'</code></p>
  
  <p>How do I add the Microsoft.Office.Core package to my asp net core 2.0 application?</p>