Android Studio 3.2.1 reporting in:
solved the issue by resetting SDK.
Preferences -> Appearance & Behavior -> System Settings -> Android SDK.
Click on Edit to the right of Android SDK location.
Next, Next, Finish to complete the wizard and voila!
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…