How to access the Print to PDF button when viewing completed task forms where the button is unavailable.
Add a 'Cancel' button with 'Visible on View Mode' selected in Advanced settings.
Give it the hide rule: [ or(Is New Mode, or(Is View Mode, Is Display Mode)) ]
The button will not show up on the form, as it will be disabled when viewing the task form, however Print to PDF will now be enabled.Note: This will only effect task forms that are created in future workflows. It will not retroactively effect existing task forms.
This is due to a known issue with Print to PDF and task forms. If there is no button on the form that is 'Visible on View Mode' then Print to PDF will be disabled for completed tasks.