Gradle project sync failed basic functionality will not work : How to fix (Android Studio)
In Android Studio there comes a Gradle compilation error because " Android support repository" is not installed by default. So you will get the below errors.
"Gradle project sync failed: basic functionality (eg. editting, debugging) will not work"
"Failed to Find: com.android.support:appcompat-v7:20.+"
To fix this error, install Android support repository from "Android SDK manager"