I have created a content type for "Seminars" which allows me to define a training seminar that occurs on one day only (start date only) or on multiple days (start and end date). Also, the same seminar can occur on multiple dates.
When I set up the most basic calendar possible (choice of field from the template, and that's it), and choose the "month" display, I get the following error message:
Warning : Illegal string offset 'data' dans template_preprocess_calendar_month() (ligne 38 dans G:\wamp\www\d7igpde\sites\all\modules\calendar\theme\theme.inc).
In fact it appears for line 38 and line 43