Reported in KAlarm forum: https://forum.kde.org/viewtopic.php?f=229&t=161065&sid=14561f16894657f31191970140131294 Command alarms work, but display alarms do not. I create a simple message to pop up in a minute or two. When the time arrives there is no message displayed but the entry is removed from the list as I think might be expected. Also, when I click the "Try" button to test it, nothing happens and no popup occurs. There is no error message. When I logged on in a Plasma session. I got "all shell packages missing" but the blank black desktop was quickly overlaid with three KAlarm test display messages that I had created yesterday. SOFTWARE/OS VERSIONS Linux Mint 19 Tara (based on Ubuntu 18.04 LTS), Gnome Then installed korganizer, plasma-workspace, kalarm (probably KDE Applications 17.12.3, KAlarm 2.11.16) echo $XDG_SESSION_TYPE gives: x11 echo $DESKTOP_SESSION gives: xfce
I can't reproduce this on Neon, either with KDE or XFCE as the desktop. Some sort of system configuration issue seems like the most likely explanation.