Why a converted calendar sometimes stops updating

A small share of converted calendars eventually stop refreshing. In almost every case the cause is the same: the original Outlook publish link was reset or revoked in Microsoft 365, so there's nothing left for us to fetch.

How to tell: open your original Outlook .ics link in a browser. If it no longer downloads a calendar file, the source link is dead.

The fix: re-publish the calendar in Outlook (Settings → Calendar → Shared calendars), then convert the new link again and update your subscription. We're also improving how we detect and surface these stale-source cases automatically.