title: android studio error: sdk tools directory is missing
body: <p>I installed android studio 3.0.1 on a clear windows 10.</p>
  
  <p>after install ask me to choose sdk directory location and suggested to me a default path:</p>
  
  <pre><code>C:\Users\saeid\AppData\Local\Android\Sdk
  </code></pre>
  
  <p>and I don't change that path and clicked on next button and in the next page show me this error:</p>
  
  <pre><code>Nothing to do! 
  SDK tools directory is missing
  </code></pre>
  
  <p>now everytime I run android studio ask me to specify the sdk path. and I even reinstalled it but my problem didn't solve.</p>
  
  <p>exactly what I must do ??</p>