Apple seems to have had some problems for several hours, especially on the App Store. This concerns app purchases, integrated purchases, and the iTunes Store also seems to be affected.
We can also see onthe service status pageApple’s App Store service has turned yellow. However, we have seen no problems with app updates, or with certain downloads … yet.
Some users, including us, are indeed unable to validate purchases in the applications.
Let us know in the comments if you are affected by these issues.