title: Unresolved reference to symbol in Wix
body: <p>I am trying to create a installer for MVC4 application using Wix. I found an example that shows how to create an installer for a MVC4 Application at <a href="https://github.com/BartDM/WIXInstallerDemo" rel="nofollow noreferrer">this link</a></p>
  
  <p><strong>But when I try to build the Wix Setup Project, it gives me errors like below</strong></p>
  
  <pre><code>Error   16  Unresolved reference to symbol 'WixComponentGroup:MyWebWebComponents' 
  in section 'Product:{D16E42B5-3C6F-4EE5-B2F4-727BF8B74A92}'.    
  C:\Users\Baris\Desktop\New folder\WIXInstallerDemo-master\DemoWebsite.Setup\Product.wxs 15  
  1   DemoWebsite.Setup
  
  Error   17  Unresolved reference to symbol 'WixComponentGroup:DemoWebsiteIssConfiguration' 
  in section 'Product:{D16E42B5-3C6F-4EE5-B2F4-727BF8B74A92}'.    
  C:\Users\Baris\Desktop\New folder\WIXInstallerDemo-master\DemoWebsite.Setup\Product.wxs 16  
  1   DemoWebsite.Setup`
  </code></pre>
  
  <p><strong>I tried adding WixUIExtension as a reference but it doesn't work.</strong></p>
  
  <p><strong>This is the Product.wxs. And feature node's children nodes causes this error</strong></p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="UTF-8"?&gt;
      &lt;Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"&gt;
      &lt;Product Id="{D16E42B5-3C6F-4EE5-B2F4-727BF8B74A92}" Name="Demo website setup" Language="1033" Version="1.0.0.0" Manufacturer="Me" UpgradeCode="9279b740-8419-45c4-9538-6a45f8e949c7"&gt;
      &lt;Package InstallerVersion="200" Compressed="yes" InstallScope="perMachine" /&gt;
  
      &lt;MajorUpgrade DowngradeErrorMessage="A newer version of [ProductName] is already installed." /&gt;
      &lt;Media Id="1" Cabinet="DemoWebsite.cab" EmbedCab="yes" /&gt;
  
      &lt;Property Id="DB_USER" Value="sa"/&gt;
      &lt;Property Id="DB_PASSWORD" Value="sa"/&gt;
      &lt;Property Id="DB_SERVER" Value="LOCAL"/&gt;
      &lt;Property Id="DB_DATABASE" Value="DemoWebsite"/&gt;
  
      &lt;Feature Id="ProductFeature" Title="DemoWebsite.Setup" Level="1"&gt;
        &lt;ComponentGroupRef Id="MyWebWebComponents" /&gt;
        &lt;ComponentGroupRef Id="DemoWebsiteIssConfiguration" /&gt;
      &lt;/Feature&gt;
      &lt;!-- Specify UI --&gt;
      &lt;UIRef Id="MyUI" /&gt;
      &lt;Property Id="WIXUI_INSTALLDIR" Value="INETPUB" /&gt;
    &lt;/Product&gt;
  
    &lt;Fragment&gt;
      &lt;!-- Will default to C:\ if that is the main disk--&gt;
      &lt;Directory Id="TARGETDIR" Name="SourceDir"&gt;
        &lt;!-- Will reference to C:\inetpub--&gt;
        &lt;Directory Id="INETPUB" Name="Inetpub"&gt;
          &lt;!-- Will reference to c:\Inetpub\Demowebsite--&gt;
          &lt;Directory Id="INSTALLFOLDER" Name="DemoWebsite"&gt;
          &lt;/Directory&gt;
        &lt;/Directory&gt;
      &lt;/Directory&gt;
    &lt;/Fragment&gt;
  &lt;/Wix&gt;
  </code></pre>
  
  <p>What am I doing wrong? I know its very specific for SO but I cannot find any solution on the web.</p>
  
  <p>I am using VS 2012- Wix 4.0</p>