How to Solve Gradle Sync Failed Error in Android Studio | How do I Fix Gradle Prob in Android Studio

What should I do to overcome a syncing error with Gradle in Android Studio? How do I fix gradle error in Android 2.1? How do I resolve Gradle Build Error in Android Studio 1.3.2? How do I resolve this gradle related error after updating to Android Studio 2.0? What are ways to update Android 2.3.6 to the 4.2 version? How do you remove app icons on Android 2.2? How can I change the Android Studio version from 2.3.3 to 2.1.2? How do I fix “Gradle sync failed. Could not connect