Problems with sync contacts from oc 9.0.4

[w3bservice]

SYNCHRONIZATION INFO
Synchronization phase: 9
Account name: rosalie.tannenberg@gmail.com
Authority: com.android.contacts

EXCEPTION:
java.lang.IllegalStateException: [Error 15] PREF parameter value is malformed and could not be parsed. Retrieve its raw text values instead by calling property.getParameters().get("PREF").
	at ezvcard.parameter.VCardParameters.getPref(VCardParameters.java:1019)
	at ezvcard.property.VCardProperty.getPref(VCardProperty.java:413)
	at ezvcard.property.Email.getPref(Email.java:110)
	at at.bitfire.vcard4android.AndroidContact.insertEmail(AndroidContact.java:847)
	at at.bitfire.vcard4android.AndroidContact.insertDataRows(AndroidContact.java:704)
	at at.bitfire.davdroid.resource.LocalContact.insertDataRows(LocalContact.java:98)
	at at.bitfire.vcard4android.AndroidContact.create(AndroidContact.java:633)
	at at.bitfire.davdroid.syncadapter.ContactsSyncManager.processVCard(ContactsSyncManager.java:452)
	at at.bitfire.davdroid.syncadapter.ContactsSyncManager.downloadRemote(ContactsSyncManager.java:360)
	at at.bitfire.davdroid.syncadapter.SyncManager.performSync(SyncManager.java:170)
	at at.bitfire.davdroid.syncadapter.ContactsSyncAdapterService$ContactsSyncAdapter.sync(ContactsSyncAdapterService.java:64)
	at at.bitfire.davdroid.syncadapter.SyncAdapterService$SyncAdapter.onPerformSync(SyncAdapterService.java:87)
	at android.content.AbstractThreadedSyncAdapter$SyncThread.run(AbstractThreadedSyncAdapter.java:259)
Caused by: java.lang.NumberFormatException: Invalid int: ""
	at java.lang.Integer.invalidInt(Integer.java:138)
	at java.lang.Integer.parseInt(Integer.java:358)
	at java.lang.Integer.parseInt(Integer.java:334)
	at java.lang.Integer.valueOf(Integer.java:525)
	at ezvcard.parameter.VCardParameters.getPref(VCardParameters.java:1017)
	... 12 more

SOFTWARE INFORMATION
DAVdroid version: 1.3-gplay (114) Fri Sep 02 13:40:02 MESZ 2016
Installed from: com.android.vending
JB Workaround installed: no

CONFIGURATION
System-wide synchronization: automatically
Account: rosalie.tannenberg@gmail.com
  Address book sync. interval: 240 min
  Calendar     sync. interval: 240 min
  OpenTasks    sync. interval: 240 min
  WiFi only: false
  [CardDAV] Contact group method: GROUP_VCARDS
            RFC 6868 encoding: true
  [CalDAV] Time range (past days): 90
           Manage calendar colors: true

SQLITE DUMP
android_metadata
	|  locale |
	|  de_DE |
----------
settings
	|  setting | value |
----------
services
	|  _id | accountName | service | principal |
	|  5 | rosalie.tannenberg@gmail.com | carddav | https://www.w3bserversystem-one.de/owncloud/remote.php/carddav/principals/rosalie.tannenberg@gmail.com/ |
	|  6 | rosalie.tannenberg@gmail.com | caldav | https://www.w3bserversystem-one.de/owncloud/remote.php/caldav/principals/rosalie.tannenberg@gmail.com/ |
----------
sqlite_sequence
	|  name | seq |
	|  services | 6 |
	|  homesets | 7 |
	|  collections | 9 |
----------
homesets
	|  _id | serviceID | url |
	|  6 | 5 | https://www.w3bserversystem-one.de/owncloud/remote.php/carddav/addressbooks/rosalie.tannenberg@gmail.com/ |
	|  7 | 6 | https://www.w3bserversystem-one.de/owncloud/remote.php/caldav/calendars/rosalie.tannenberg@gmail.com/ |
----------
collections
	|  _id | serviceID | url | readOnly | displayName | description | color | timezone | supportsVEVENT | supportsVTODO | sync |
	|  7 | 5 | https://www.w3bserversystem-one.de/owncloud/remote.php/carddav/addressbooks/rosalie.tannenberg@gmail.com/Adressbuch/ | 0 | Adressbuch | <null> | <null> | <null> | <null> | <null> | 1 |
	|  8 | 6 | https://www.w3bserversystem-one.de/owncloud/remote.php/caldav/calendars/rosalie.tannenberg@gmail.com/default/ | 0 | default | <null> | <null> | <null> | 1 | 1 | 1 |
	|  9 | 6 | https://www.w3bserversystem-one.de/owncloud/remote.php/caldav/calendars/rosalie.tannenberg@gmail.com/contact_birthdays/ | 1 | Contact birthdays | <null> | -54 | <null> | 1 | 1 | 1 |
----------

SYSTEM INFORMATION
Android version: 5.1.1 (cm_serranoltexx-userdebug 5.1.1 LMY48Y 69322f6ccc test-keys)
Device: Samsung GT-I9195 (serranoltexx)

[rfc2822]

Duplicate of OwnCloud returns invalid PREF value, please follow up there.