unable to download purchases in appletv app

I am trying to download video purchases on my iPad using the AppleTV app. When I try to download an episode of a purchased series, i see the error message: “ Purchase of the item is not currently available. This item is being modified. Please try again later.” This started happening after the latest ios update in the last day or so. What is the reason for this? What can I do to restore the ability to download purchases?