This version of Unity is unsupported.
Method group is Obsolete

WWW.GetAudioClipCompressed

Obsolete public AudioClip GetAudioClipCompressed();
Obsolete public AudioClip GetAudioClipCompressed(bool threeD);
Obsolete public AudioClip GetAudioClipCompressed(bool threeD, AudioType audioType);

Description

OBSOLETE. Use UnityWebRequestMultimedia.GetAudioClip().