update

Assets/Editors/ProjectAudioPreview.cs

@@ -21,6 +21,7 @@
 // 3. Hover over any AudioClip; a Play/Stop icon will appear on the right side.
 // ===============================================================================
 
+#if UNITY_EDITOR
 using UnityEditor;
 using UnityEngine;
 using System;
@@ -160,4 +161,5 @@ namespace EditorTools
             }
         }
     }
-}
+}
+#endif