Thanks for the link.
I guess the main problem is, no calendar is localy created.
So i cant sync the cloud calendar with local one 
There is no entry inside the samsung calendar.
04-08 11:37:14.594 5328 5328 E Layer : [Surface(name=AppWindowToken{27c5792 token=Token{6b391d ActivityRecord{27cdf4 u0 com.sec.android.app.launcher/.activities.LauncherActivity t1786}}})/@0xc2007d1 - animation-leash#0] No local sync point found
04-08 11:37:14.594 5328 5328 E Layer : [Surface(name=AppWindowToken{a2c1e7e token=Token{ceb5839 ActivityRecord{e7ec800 u0 at.bitfire.davdroid/.ui.account.AccountActivity t1798}}})/@0x27728c7 - animation-leash#0] No local sync point found
04-08 11:37:14.594 5328 5328 E Layer : [Surface(name=478db6b com.android.systemui.ImageWallpaper)/@0x7389ae - animation-leash#0] No local sync point found
E BufferQueueProducer: [at.bitfire.davdroid/at.bitfire.davdroid.ui.account.AccountActivity$_12835#0] disconnect: not connected (req=1)