There is Check necessity the check box "Delete all under selection" in the Preferences window to delete Category, Table data one degree.
Preferences window opens with the Press in this order.
menubar -> [Chronica] -> [Preferences]
When the check box "Delete all under selection" in the Preferences window is checked, the category, table has the data can be deleted at a time.
When the check was missed, the category, table which has the data cannot be deleted at a time.
