Is the issue that music you downloaded is unplayable offline? If so, please contact us here with more details.
Or is is that music is being taken off the app due to copyright infringement, and so it's no longer in your downloads? If so, it's likely because that music was unfortunately uploaded without the artists' permission and had to be taken down from Audiomack. We apologize for the inconvenience, and we are working hard to license thousands of new popular songs every week.