I don't know where to look for an error log :-(

Same network, same config on all devices - same behavior when I configure only single caledar accounts - the calender is added - I can configure how often to sync, color, ... - and when I try to sync it fails - no connection can be established to [server.xxx] ...

Works perfect on sailfish, bb10, iOS, OS-X and WP8.1 - that's weird

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