Maintenance - CollectionEventSeries

To delete CollectionEventSeries with no relation to CollectionEvents or other event series choose the tab page Orphaned data -   Series. Click the List orphaned event series button to list these series. The detected data will be listed as shown below. In case there are orphaned images these must be deleted first (see below). Click on the Delete orphaned event images and and the Delete orphaned event series button to delete the data.