LaunchDate OR DiscontinueDate are in the past. For details, see http://sellercentral.amazon.co.uk/gp/help/23171
You cannot provide LaunchDate and DiscontinueDate values that are in the past. All event flags must be associated with a future date. If you are attempting to modify the LaunchDate to a past date in order to make your products available on Amazon, you should instead provide a LaunchDate equal to today. It can take up to 24 hours before your products appear on Amazon. If you are trying to discontinue a product immediately, you should instead provide a DiscontinueDate equal to today and set the available product quantity to zero.
Remember to format your date values as YYYY-MM-DD. For example, February 29, 2008 should be formatted as 2008-02-09.