Best answer by Mathis
Thanks for posting. I've looked into this for you and it looks like the track has reached its download limit of 1000 downloads. That is a limit per track, and it lies with the uploader actually. Thus, "Nature Sounds" could either upgrade to the Pro Unlimited plan (no limit on that plan), or upload the track again. Alternatively, you might reach out to the user directly and see if they have an alternate download link for you.
Hope this helps to understand why you cannot download that track right now.