Android Studio: Unable to Access Android SDK Add-on List

Add the following code to idea.properties which is located at the bin folder in the installation path of your Android Studio.

That means:

Windows: C:\Program Files\Android\Android Studio\bin\idea.properties
Mac: /Applications/Android Studio.app/Contents/bin/idea.properties

disable.android.first.run=true

idea.properties file

Save it and restart the app, it works again.