Although the error is happening, the script still runs perfectly fine and the equalizer is applied to all sounds. Why is this permission identity error happening? Is it because scripts aren’t allowed to access the ClassName of certain game objects? I tried :IsA() too.
Some services and their descendants (for example, CoreGui) are RobloxLocked, and since normal scripts can’t do anything with such instances, it throws an error.
To solve this, use GetDescendants() only on services where sounds can be located (workspace, SoundService, maybe somewhere else, etc.)
Also, why do you use spawn() in this case? Your code doesn’t yield, so I think it’s useless here.