Announcements of webinars contain .ics files that, when clicked on, create an event in KOrganizer. Unfortunately, KOrganizer seems to lose all events regularly. Changed preference in Firefox and Thunderbird to handle .ics files with Thunderbird. Lightning does not appear in the options list for Edit/Preferences/Applications/ VCS/ICS/Other so I selected Thunderbird. The only app named lightning in the openSuse repositories is a data base. Now, clicking on an ICS file opens a new email in Thunderbird, with the ICS file attached. Clicking on the attachment opens another new email. Oddly, the calendar does contain some events that arrived as invitations to an event, with a button displayed to Accept Now. However, an email with file.ics as an attachment doesn't do anything but open new emails. What am I missing?