title: .NET Runtime Version Issue (supportedRuntime)
body: <p>First, I´ve found a few questions on this topic but none seem to address exactly my issues, but feel free to point to an existing question if you feel it does answer my questions.</p>
  
  <p>My problem: I am building a C# .NET app that depends on .NET Framework 3.5 <strong>or above</strong>. My main problem is on the "or above" part.</p>
  
  <p>The app was working perfectly if the target machine had exactly the version 3.5 installed (and I hadnt changed anything on the app.config). But now I tested on a machine that has 4.0 only (ie, doesnt have 3.5) and it didnt work, it says:</p>
  
  <p>"Unable to find a version of the runtime to run this application."</p>
  
  <p>And, btw, my installer detects that there is a compatible .NET version (ie, a version >= 3.5), so it allows the app to install, but it wont run after installed.</p>
  
  <p>Then researching I found out that you had to change app.config and add the other .NET Framework versions, so I added:</p>
  
  <p>supportedRuntime version="v4.0.30319"</p>
  
  <p>(full app.config:</p>
  
  <pre><code> &lt;?xml version="1.0"?&gt;
      &lt;configuration&gt;
      &lt;startup&gt;
        &lt;supportedRuntime version="v4.0.30319"/&gt;
        &lt;supportedRuntime version="v2.0.50727"/&gt;
      &lt;/startup&gt;
      &lt;/configuration&gt;
  </code></pre>
  
  <p>)</p>
  
  <p>After I added this, I started getting warnings saying "Could not find schema information for the attribute "version" (and element "supportedRuntime")", and when I run it on the .NET-4.0-only-machine it will give me the same error message as before.</p>
  
  <p>My project is set to 3.5 as target-runtime on project properties.</p>
  
  <p>Any ideas?</p>
  
  <p>Thanks in advance.</p>