title: How to resolve Android Studio cannot find JAR 'core-3.1.1.jar' required by module 'gradle-jetty?
body: <p>I opened up Android Studio today and for the first time I saw this error:<br>
  Error:Cannot find JAR 'core-3.1.1.jar' required by module 'gradle-jetty' using classpath or distribution directory '/Applications/Android Studio.app/Contents/gradle/gradle-2.14.1'</p>
  
  <p>I have tried, restarted both my Mac and Android Studio but yet I still get this error. Can anyone help me?</p>