Owncloud -> Android 5.0 -> Open Tasks => results in 500 Internal Server Error

[DkDe]

This happens always and only a Samsung Galaxy S5, when I turned off task (aufgaben) syncing, the rest calendar+carddav runs fine. At the same Time two Samsung Devices with Android 4.x had no problems on syncing tasks.

Bugreport: http://ur1.ca/oqtmw

[rfc2822]

1. Your error report is not related to tasks, but the calendars (Authority: com.android.calendar, request is for VEVENT).
2. This is an internal server error, possibly for the same reason as https://forums.bitfire.at/topic/1024/owncloud-this-recurrence-rule-does-not-generate-any-valid-instances/ and https://forums.bitfire.at/topic/1031/caldav-sync-no-longer-works-backtrace-with-owncloud-7-0-4-after-update-to-davdroid-1-x/. Please see there for a workaround.