If you have doubts about the calendar, create a new one called e.g. "test" and create in this new calendar a new event filled with anything with an alarm for 30 days before.
If the alarm window shows, then I would say to move one by one each event from the old calendar to the new (but this won't do anything) or recreate the events with trouble.
If the alarm doesn't show submit here the calendar file with the one event. But again, I don't think that here's the problem.
Are the events old? I mean, did you dismiss or snooze the event at least once?
Or search in the user folder (FAQ
) for the .ics file, open it with a text editor, search for the problematic event (BEGIN:VEVENT ... END:VEVENT) and paste here ONLY this event (CHANGE ANY SUBJECT OR DESCRIPTION IF PRIVATE BEFORE
). This will show if there's something wrong with the event data.