Caldav: Job event-reloader.command threw an unhandled Exception

Hi,
caldav seems not be able to load m owncloud calendar entries. Because of inconsistencies between caldav and owncloudI deleted etc/caldav/-entries and restarted openhab. Since than I’m not able to see any calendar entries.This error appears for all my four calendars.

2016-10-18 08:16:03.460 [ERROR] [org.quartz.core.JobRunShell ] - Job event-reloader.command threw an unhandled Exception:
java.util.ServiceConfigurationError: net.fortuna.ical4j.model.PropertyFactory: Provider net.fortuna.ical4j.model.property.Action$Factory not a subtype
at java.util.ServiceLoader.fail(ServiceLoader.java:239) ~[na:1.8.0_101]
at java.util.ServiceLoader.access$300(ServiceLoader.java:185) ~[na:1.8.0_101]
at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:376) ~[na:1.8.0_101]
at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404) ~[na:1.8.0_101]
at java.util.ServiceLoader$1.next(ServiceLoader.java:480) ~[na:1.8.0_101]
at net.fortuna.ical4j.model.AbstractContentFactory.getFactory(AbstractContentFactory.java:85) ~[na:na]
at net.fortuna.ical4j.model.PropertyFactoryImpl.createProperty(PropertyFactoryImpl.java:78) ~[na:na]
at net.fortuna.ical4j.data.CalendarBuilder$ContentHandlerImpl.startProperty(CalendarBuilder.java:326) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl$PropertyParser.parse(CalendarParserImpl.java:206) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl$PropertyParser.access$1100(CalendarParserImpl.java:190) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl$PropertyListParser.parse(CalendarParserImpl.java:173) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl.parse(CalendarParserImpl.java:122) ~[na:na]
at net.fortuna.ical4j.data.CalendarBuilder.build(CalendarBuilder.java:198) ~[na:na]
at org.openhab.io.caldav.internal.job.EventReloaderJob.loadEvents(EventReloaderJob.java:307) ~[na:na]
at org.openhab.io.caldav.internal.job.EventReloaderJob.loadEvents(EventReloaderJob.java:290) ~[na:na]
at org.openhab.io.caldav.internal.job.EventReloaderJob.execute(EventReloaderJob.java:126) ~[na:na]
at org.quartz.core.JobRunShell.run(JobRunShell.java:213) ~[quartz-all-2.1.7.jar:na]
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:557) [quartz-all-2.1.7.jar:na]
2016-10-18 08:16:03.466 [ERROR] [org.quartz.core.ErrorLogger ] - Job (event-reloader.command threw an exception.
org.quartz.SchedulerException: Job threw an unhandled exception.
at org.quartz.core.JobRunShell.run(JobRunShell.java:224) ~[quartz-all-2.1.7.jar:na]
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:557) [quartz-all-2.1.7.jar:na]
Caused by: java.util.ServiceConfigurationError: net.fortuna.ical4j.model.PropertyFactory: Provider net.fortuna.ical4j.model.property.Action$Factory not a subtype
at java.util.ServiceLoader.fail(ServiceLoader.java:239) ~[na:1.8.0_101]
at java.util.ServiceLoader.access$300(ServiceLoader.java:185) ~[na:1.8.0_101]
at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:376) ~[na:1.8.0_101]
at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404) ~[na:1.8.0_101]
at java.util.ServiceLoader$1.next(ServiceLoader.java:480) ~[na:1.8.0_101]
at net.fortuna.ical4j.model.AbstractContentFactory.getFactory(AbstractContentFactory.java:85) ~[na:na]
at net.fortuna.ical4j.model.PropertyFactoryImpl.createProperty(PropertyFactoryImpl.java:78) ~[na:na]
at net.fortuna.ical4j.data.CalendarBuilder$ContentHandlerImpl.startProperty(CalendarBuilder.java:326) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl$PropertyParser.parse(CalendarParserImpl.java:206) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl$PropertyParser.access$1100(CalendarParserImpl.java:190) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl$PropertyListParser.parse(CalendarParserImpl.java:173) ~[na:na]
at net.fortuna.ical4j.data.CalendarParserImpl.parse(CalendarParserImpl.java:122) ~[na:na]
at net.fortuna.ical4j.data.CalendarBuilder.build(CalendarBuilder.java:198) ~[na:na]
at org.openhab.io.caldav.internal.job.EventReloaderJob.loadEvents(EventReloaderJob.java:307) ~[na:na]
at org.openhab.io.caldav.internal.job.EventReloaderJob.loadEvents(EventReloaderJob.java:290) ~[na:na]
at org.openhab.io.caldav.internal.job.EventReloaderJob.execute(EventReloaderJob.java:126) ~[na:na]
at org.quartz.core.JobRunShell.run(JobRunShell.java:213) ~[quartz-all-2.1.7.jar:na]
… 1 common frames omitted

I’m using openhab 1.8.3 with the corresponding binding versions (no nightly builds). I didn’t change anything to the configuration since months.Is there an obvious error I made or is it a bug?