Getting "Ask your admin to add https://domain.com/path_to_calendar to the allowlist" error when subscribing to external calendar
Platform notice: Server and Data Center only. This article only applies to Atlassian products on the Server and Data Center platforms.
Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Summary
In Team Calendars, when attempting to subscribe to external calendar by URL (i.e pagerduty), user is receiving this error:
You can't subscribe to this calendar. Ask your admin to add https://domain.com/path_to_calendar to the allowlist.
Cause
Calendar service is not properly added to the Allowlist
Solution
Go to Settings > General Configuration > Allowlist and add domain for the calendar service. Make sure URL is absolute without any trailing "/", i.e http://domain.com