When creating an ask ladder, users can choose to base the ladder on a smart field. This smart field may be the last donation amount, total donations, etc., and the appropriate ask value will be selected based on this.
The Marketing Acknowledgements are failing to populate an ask value in the export if a smart field is used. Static ask values work correctly.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.