Microsoft.Office.Core Reference Missing

Solution 1:

You can add reference of Microsoft.Office.Core from COM components tab in the add reference window by adding reference of Microsoft Office 12.0 Object Library. The screen shot will shows what component you need.

Solution 2:

None of the above answer helped me, i was using Visual Studio 2017. What I did is, installed Office/SharePoint Development using Visual Studio Installer.

After that, I was able to see 'office', this assembly contains Microsoft.Office.Core.

Hope this helps you.

Solution 3:

You need to download and install the PIA (primary interop assemblies) for the version of Office you are using. Once installed you can then add a reference to your project and they will be available from the add reference dialog. Here are the links to download them...

Office 2010 PIA

Office 2007 PIA

Office 2003 PIA