It appears that the prior year templates have been updated - along with the 2019 T5 slip template - on CRA’s end. Updating the prior year templates in ProFile won’t permit for the filing of prior year T5 slips…ProFile can only update the templates for the current tax year supported. As a result, we do not plan to fix the 2017 or 2018 T5 slip issue.
If you have not already done so, paper file the prior year T5 slips with CRA.
A template change for a common slip is rare and we are sorry you had to experience this issue. We thank you for being a ProFile customer and have a great tax season.