If your internet is offline,
In such a case, you can work with other maps, and even can close the map with modified calendar topics.
When the Internet connection returns, you can manually refresh the modified calendar topics or wait for an Autorefresh.
When Refreshing any calendar topic(s) or Autorefreshing, Calendar Manager synchronizes all created/modified/deleted offline calendar topics from all maps ((including closed maps).
Autorefresh does not work in offline mode.