IndexOutOfRangeException: Array index is out of range

Hello, My console screen gave me a that error.
“IndexOutOfRangeException: Array index is out of range.
MusicManager.OnLevelWasLoaded (Int32 level) (at Assets/Scripts/MusicManager.cs:20)”

Can anyone help me? I am using Unity 2018 by the way.

Thanks…

Are your levels added to build index ?
Is the level index called exists ?

1- Delete the Music player from your splash scene (you do not need it there)
2- Go to the start scene and set the array size to 4 and then attach the music at the 1st element