After the last update of Kuguntu 20.04 Kalarm don't start. The problem is "Il servizio Akonadi per la gestione delle informazioni personali non è operativo".
This problem should not exist in Kubuntu 20.10 and later, because KAlarm no longer uses Akonadi to access its calendars (from KAlarm version 3.0/KDE apps 20.08 onwards). This seems likely to be a problem which will occur with any application which uses Akonadi (KMail, KOrganizer, etc.), since they all use the same Akonadi database to access their data. See for example https://askubuntu.com/questions/1255772/kmail-cant-start-akonadi-services-on-kubuntu-20-04. There is a possible solution at https://forum.kde.org/viewtopic.php?t=111828#p268167 To investigate, try the following: 1) If I remember correctly, there is a button in the application window which you can click to get more information about why Akonadi cannot run. This may help to understand what to do to fix the issue. 2) If that doesn't help, you could open a terminal window (e.g. Konsole), and type akonadictl start Then, in the terminal window, look for error messages which help you to understand why Akonadi cannot run.