title: SSDT installer missing prerequisite: SQL Server 2016 System CLR Types
body: <p>I have attempted installing an update to Microsoft SQL Server Data Tools into Visual Studio 2015 Professional. Upon doing so I receive the following error message:</p>
  
  <blockquote>
    <p>Setup is missing an installation prerequisite:<br>-Microsoft SQL Server 2016 System CLR Types. To continue, install SQL Server 2016 System CLR Types from <a href="http://go.microsoft.com/fwlink/?LinkID=398158" rel="nofollow noreferrer">http://go.microsoft.com/fwlink/?LinkID=398158</a> and then run the Setup operation again.</p>
  </blockquote>
  
  <p>The hyperlink provided by Microsoft actually takes me to Microsoft SQL Server 2014 Feature Pack. Nonetheless, I continue to install <code>ENU\x64\SQLSysClrTypes.msi</code>. Just to be extra sure, I navigated to <a href="https://www.microsoft.com/en-us/download/details.aspx?id=52676" rel="nofollow noreferrer">Microsoft SQL Server 2016 Feature Pack</a> and installed <code>ENU\x64\SQLSysClrTypes.msi</code> from the latest version of SQL Server.</p>
  
  <p>When running the SQL Server Data Tools installer again I receive the same fatal error in the installer message and log file. The log file reports the error code <code>0x80070643</code>. The most helpful article I have found relating this issue is <a href="https://support.microsoft.com/en-gb/kb/976982" rel="nofollow noreferrer">KB976982</a>. I have tried running the Microsoft .NET Framework Repair Tool; the tool failed to resolve the problem and I am continuing to work through it.</p>