Seems to be an OwnCloud problem. Please follow up at https://github.com/owncloud/contacts/issues/1011.
Error notification on syncing calendar from/to nextcloud 10.0.1
Started to test DAVdroid for syncing CalDAV/CardDAV with nextcloud 10.0.1. Server works flawless with thunderbird/lightning and android with alternative CaldDAV/CardDAV sync.
Calendar sync does work, but throwing ‘notification error’ like here:
java.lang.IllegalArgumentException: Invalid int: “T0”
There’s an invalid iCalendar resource which can’t be parsed correctly. Please fix your iCalendar resources. You can use verbose logging to find the erroneous resource.
You are right. I found the problematic ressource, it was a recurrent event.
Thanx for your help!