Why: We Couldn’t Make Your Purchases Available – iTunes
Did you receive a warning in iTunes (top right corner) that iTunes is unable to make your purchases available? The error is listed below.
We couldn’t make your purchases available. Click on the retry button.
If you already clicked on the retry button but you still receive the error, check the Apple system status website (here) for any current downtime Apple is experiencing. This would likely be an issue with the iTunes Store.