When you are at https://www.scoutbook.com/mobile/dashboard/calendar/ and click on a Subscribe link, a modal dialog comes up inviting the user to subscribe to a calendar URL. It presents a clickable iCal link.
This is bad UI. Why? With a clickable link, the UI is inviting the user to do the wrong thing: download the ICS file and then add that to their calendar.
The fix is easy: just remove the a tag around the URL to the ICS file. There is almost never a reason why anyone should download the ICS file, so the UI should not even make it feasible.