title: "Error Opening SDF File" For Any and All C++ Projects in VS2015
body: <p>Any C++ projects I create or open in VS2015, I get this error:</p>
  <blockquote>
  <p>An error occurred while creating or opening the C++ browsing database file WHATEVER.sdf. IntelliSense and browsing information will not be available for C++ projects.</p>
  <p>Ensure that Microsoft SQL Server Compact 4.0 is installed and that no other applications are accessing the file. If this problem persists, delete the file and reopen the solution.</p>
  </blockquote>
  <p>Which means that there is no IntelliSense, etc. which is half the reason I use Visual Studio in the first place. I'm using Visual Studio 2015 Enterprise edition on Windows 8.1, and this happens for <em>all</em> C++ projects. The SDF file doesn't actually get created at all, so there is no file to delete.</p>
  <p>What I have tried so far; none had any effects:</p>
  <ul>
  <li>Making sure SQL Server Compact 4.0 is actually installed (it was.) The version was 4.0sp1, which I tried replacing with 4.0 anyways, but it informed me that a newer version already existed and nothing needed to be done.</li>
  <li>Running VS with elevated (administrator) privileges.</li>
  <li>Creating projects in different directories (e.g. under the default VS project path, in the root of a drive, on another drive, on paths with no spaces in them, etc.)</li>
  <li>Repairing Visual Studio installation (twice.)</li>
  <li>Using the &quot;fallback location&quot; for the SDF file (under Tools-&gt;Options-&gt;Text Editor-&gt;C/C++-&gt;Advanced-&gt;Fallback Location) with exactly the same effect.</li>
  </ul>
  <p>Running VS (<code>devenv.exe</code>) with <code>/Log</code> command line option and opening a project and then closing VS gives me a 600KB+ XML file, which I can't read, and a cursory search revealed no suspicious entries.</p>
  <p>Any hints/suggestions/solutions?</p>