Due to an owncloud error (https://github.com/owncloud/contacts/issues/585) my dav resources failed to sync and goes offline. Unfortunately I got no message about this so that I assume that my contacts and events are in sync with the server. This can lead to a data loss. It would be good, if there is a popup or dialog when there is any sync error which makes the resource offline. The imap resources behave like this.
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