After reading your posts, I got it to work by changing the order of the dates. Instead of showing 12 months starting in 2018 going into 2019, I show it as 12 months going backwards from 2019 into 2018. It looks like the program will only work if you have 2019 as the date you enter first, and not 2018, even though CRA allows 2018 within a 12 month period. Kind of weird to send it in this way, but at least it's reflecting the medical expenses now.