Purchased multiple soundpacks but they won't insrall. They will download, say download complete but won't install. Already received email confirming purchase but still can't use them.
For some users, the installation process of an in-app store item just sometimes seems to get stuck in the way you described. It's not a problem specific to the content item you picked. Just seems to be an intermittent issue that strikes sometimes, and that we haven't really managed to trace back to any specific causes yet. From my experience, this always helps: Open the program settings within Music Maker and use the "Clean up Store..." button in the "General options" tab. After the application has restarted, sign back into your account, and download/install the item again. That should do the trick.