Unitywebrequest returns fmod error

I’m trying to make an audioloader so the user can choose his/her own music, but i’m running into a problem i don’t know how to solve. Whatever audioformat i try, unity will always say the file format is not supported. I’m currently using 2018.2, but in earlier versions unity would just give me a blank error and not tell me anything. Here’s my code, i copied the entire thing straight from this Unity - Scripting API: Networking.UnityWebRequestMultimedia.GetAudioClip, and added a delay so the requester can finish downloading, any ideas? The file does exist, it plays when i click it.

IEnumerator GetAudioClip(string directory)
{
    using (UnityWebRequest www = UnityWebRequestMultimedia.GetAudioClip("file://D:/audio.wav", AudioType.WAV))
    {
        
        yield return www.SendWebRequest();
        while (!www.isDone)
        {
            yield return new WaitForEndOfFrame();
        }

        if (www.isNetworkError)
        {
            Debug.Log(www.error);
        }
        else
        {
            AudioClip myClip = DownloadHandlerAudioClip.GetContent(www);
            transform.GetComponent<AudioSource>().clip = myClip;
            transform.GetComponent<AudioSource>().Play();
        }
    }
}

Same with me I’ve been three days with this problem