title: VS 2012 Publish: Can't find the valid AspnetMergePath
body: <p>I just installed Update 2 for Visual Studio 2012, which introduces a new Publish dialog. I'm trying to make it do what it used to do (precompile a website before publishing), and I'm running into the error that it </p>
  
  <pre><code>"Can't find the valid AspnetMergePath"
  </code></pre>
  
  <p>which is thrown from the file Microsoft.Web.Publishing.AspNetCompileMerge.targets. I've confirmed that the file aspnet_merge.exe exists in multiple places on my computer, but</p>
  
  <pre><code>$(GetAspNetMergePath) 
  </code></pre>
  
  <p>is evaluating to an empty string for some reason. I must be missing some configuration setting, but I've never messed with those before, so I'm confused as to why this would start suddenly.</p>
  
  <p>Can anyone offer advice on how to resolve this? I've done the standard Google searching on this error and nothing has led me to the right solution.</p>