Percentage off extra product not working

[Sail and Ski]

I am trying to set up a discount so when customers spend £100 they get a free thermal top, as far as I can see I have set it up correctly but when I press apply an error message comes up saying "Extra Product/Product Group must be defined for the selected reward type".

I have selected the product group so really can't see what has gone wrong! See picture for how it is set up, any help would be greatly appreciated!

Ben

[JFro]

I am having the same issue with that error message - wanting to add a free gift sample when a customer orders a specific product...