title: Cordova 4.3.0 Error: Please install Android target: "android-21"
body: <p>I have a project that is running well with ripple emulator, but when i try to launch it on a physical Android device, I get the following error : </p>
  
  <blockquote>
    <p>Error: Please install Android target: "android-21". </p>
    
    <p>Hint: Open the SDK manager by running: C:\Program\ Files\ (x86)\Android\android-
    sdk\tools\android.BAT</p>
    
    <p>You will require:</p>
    
    <ol>
    <li>"SDK Platform" for android-21</li>
    <li>"Android SDK Platform-tools (latest)</li>
    <li>"Android SDK Build-tools" (latest)</li>
    </ol>
    
    <p>ERROR running one or more of the platforms: Error: cmd: Command failed with exit code 2
    You may not have the required environment or OS to run this project</p>
  </blockquote>
  
  <p>The device I'm using is on Android 4.2.2. The sdk installed on my computer is the 4.4.2 (API 19) : 
  <img src="https://i.stack.imgur.com/YYN4Q.png" alt="android skd"></p>
  
  <p>I don't understand why my app doesn't lauch on my device.</p>