title: Problem with update Android SDK API 28 inside Android Studio
body: <p>I want to update my Android API SDK 28 from Studio's SDK Manager . Inside the tab "SDK Platforms" I can check every Android API to instal except the first Android API 28. Can anybody explain me why it's happening?</p>
  
  <p><a href="https://i.stack.imgur.com/NvKd5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NvKd5.png" alt="SDK Platform Window"></a></p>