title: "PDB format is not supported" with .NET portable debugging information
body: <p>The last couple of days I've been <a href="https://github.com/Azure/service-fabric-aspnetcore/issues/17" rel="noreferrer">hunting down a problem</a> - with the conclusion: </p>
  
  <p><em>My Visual Studio 2017 debugger can't work with PDBs in "portable" format in .NET Framework projects.</em></p>
  
  <p>With portable format I mean going to a project's settings, then to <code>Build</code> <code>-&gt;</code> <code>Advanced</code> and then selecting <code>portable</code> under <code>Debugging information</code>.</p>
  
  <p>When I start debugging a .NET Framework project built like this, breakpoints don't get hit.</p>
  
  <p><img src="https://i.stack.imgur.com/eGCby.png" alt="The breakpoint will not currently be hit. No symbols have been loaded for this document."></p>
  
  <p>When I pause the debugger and look for the reason why it didn't load the symbols, it says (under <code>Symbol load information</code>):</p>
  
  <blockquote>
    <p>PDB format is not supported</p>
  </blockquote>
  
  <p>I can reproduce this with any .NET <em>Framework</em> project. The target framework doesn't seem to matter. I tried .NET 4.5.2 and 4.6.2.</p>
  
  <p>It works fine, though, for .NET <em>Core</em> projects.</p>
  
  <p>Now, the strange thing is that the exact same project works fine on another computer.</p>
  
  <p>So, it seems that my computer is missing something or has something misconfigured. But my Google search didn't turn up anything. Any ideas how to fix this problem?</p>