Hi GDodd
Thank you for your post. I'd like to extend you a warm welcome to the Community Forum. I hope you find it a valuable resource.
In order to resolve this error message, you can select the add condition and enter the amount. I have tried replicating it on our end, selecting the add condition and putting the amount in line to it, works. Hope it works for you too.
Please feel free to post again I'm happy to assist.
If my response has answered your enquiry please click "Accept as Solution" to assist other users find this information.
Cheers,
Princess