I am running Linux Mint, so apparently KDE was the default and Kontact is easily accessible from the left-hand corner launcher.

I started it up and told it I didn't want email.

I tried to use the TO DO list.

I was able to create todos, and they showed up in the summary pane.

I can even click the to dos in the summary pane because they appear as hyperlinks.

However, they lead to a blank calendar. After I've created these to-dos, it seems I can't read the details, I can't list them except in summary form, and I can't interact with them.
I assume Kontact is working properly and it will let me edit these todos if I just enter the right command.

Thanks.

There are alternatives to Kontact and Korganizer, such as GNOME Evolution and Lightning, but I have already installed a recent Thunderbird and the current version of Lightning is not compatible with my version of Thunderbird.