I'm syncing to Nextcloud via CalDAV with org-mode 9.0.3 and the latest org-caldav.
Events are sometimes synced (and modified in the .org file) with the prefix "S:". The symptoms are exactly like: https://github.com/dengste/org-caldav/issues/33#issuecomment-74551937 "The SCHEDULED time gets converted to an active timestamp and a freshly created property drawer with a new id is inserted above that newly created active timestamp." It looks like this prefix is being prepended by org-icalendar-entry in ox-icalendar, but I don't know enough about Lisp or org internals to debug much further. Here are my org-{icalendar,caldav} settings: (setq org-icalendar-alarm-time 30) (setq org-icalendar-use-deadline '(event-if-todo event-if-not-todo todo-due) org-icalendar-use-scheduled '(event-if-todo event-if-not-todo todo-start)) (setq org-export-exclude-category (list "dummy")) (setq org-caldav-inbox (expand-file-name "~/org/caldav-inbox.org")) (setq org-caldav-files org-agenda-files) (setq org-caldav-show-sync-results nil) (setq org-caldav-resume-aborted 'never) Is there some configuration I need to change to stop this behavior? -john