Your recurring events may have been working fine, and then suddenly - maybe at the beginning of a new year - they have all disappeared from your calendar, and you didn't change anything. 

This is easy to fix, and happens because the event series was initially set up with an end date, per the image below. 

The Events Calendar now allows you to 'never' expire the recurring event rather than requiring an end date to the series. Click the drop down next to Series ends and choose 'never'. The event plugin will automatically create your series for 24 months in the future and will keep adding new events to the end of the series over time, so it continues indefinitely - until you change or delete it. 

By default, the plugin will also trash past recurring events older than 24 months. If you have a lot of events, we recommend setting this to be 12 months instead, and also moving all events older than 12 months to trash and permanently deleting them after two years. See these settings below. This will make the calendar plugin work faster for people visiting your website. Our staff also occasionally purges all trashed articles during regular maintenance if the database is too big, and that may override your settings.