When i click on a calendar (a file .ics) and i have the kontact open, it opens the todo list module in kontact and nothing happens. If i quit kontact and i click on the file .ics (in the internet) it opens the todo module but with an import dialog this time so i can import the calendar.

Strange; it opens the dialogue as expected for me; have you got the Calendar module open at the time?

yes i tried again with the module opened, i dont have the import dialog

If you open KOrganizer directly (make sure to close Kontact first) do you have the import dialog available?

if kontact is closed then i have the import dialog

This is likely a bug in the Kontact/KOrganizer integration unfortunately. Please file a bug report at bugs.kde.org.

ok, thanks
https://bugs.kde.org/show_bug.cgi?id=267762