EndDate is invalid or in the wrong format. For detailed help with formatting, see http://sellercentral.amazon.co.uk/gp/help/24941
This error occurs when the end date for your sale is improperly formatted or invalid. For the end date to be valid, it must be:
To resolve this error, please resubmit your data using a sale end date that is properly formatted and in the valid date range.
If you are using inventory files to manage your products and sales, Microsoft Excel may have reformatted your end date when you entered it in your inventory file template. To prevent Microsoft Excel from reformatting your date: