Error with Caldav personal

Hey,
I am new here and work with openHab2 since a month and now I have a problem.

I want to use the caldav binding and connect it to my Google calender, but it does not show the date or string of the calendar entry. I get this errormesage in the log:

2020-04-01 16:38:11.253 [WARN ] [.io.caldav.internal.CalDavLoaderImpl] - Unable to parse configuration parameter: usedCalendars
2020-04-01 16:38:11.262 [ERROR] [org.apache.felix.configadmin ] - [org.osgi.service.cm.ManagedService, org.openhab.io.caldav.CalDavLoader, id=408, bundle=256/mvn:org.openhab.io/org.openhab.io.caldav/[1.14.0,1.15)]: Updating property CalDAV IO of configuration org.openhab.caldavio caused a problem: Unable to parse configuration parameter: usedCalendars
org.osgi.service.cm.ConfigurationException: CalDAV IO : Unable to parse configuration parameter: usedCalendars
at org.openhab.io.caldav.internal.CalDavLoaderImpl.updated(CalDavLoaderImpl.java:187) ~[?:?]
at org.apache.felix.cm.impl.helper.ManagedServiceTracker.updated(ManagedServiceTracker.java:189) ~[bundleFile:?]
at org.apache.felix.cm.impl.helper.ManagedServiceTracker.updateService(ManagedServiceTracker.java:152) [bundleFile:?]
at org.apache.felix.cm.impl.helper.ManagedServiceTracker.provideConfiguration(ManagedServiceTracker.java:85) [bundleFile:?]
at org.apache.felix.cm.impl.ConfigurationManager$UpdateConfiguration.run(ConfigurationManager.java:1405) [bundleFile:?]
at org.apache.felix.cm.impl.UpdateThread.run0(UpdateThread.java:138) [bundleFile:?]
at org.apache.felix.cm.impl.UpdateThread.run(UpdateThread.java:105) [bundleFile:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_222]

This is my caldavio.cfg file:

caldavio:muell:url=https://www.google.com/calendar/dav/xxx@group.calendar.google.com/events
caldavio:muell:username=xxx (without@gmail.com)
caldavio:muell:password=xxx
caldavio:muell:reloadInterval=1
caldavio:muell:preloadTime=20000
caldavio:muell:disableCertificateVerification=true
caldavio:muell:charset=UTF-8

And this is my caldavPersonal.cfg file

caldavPersonal:usedCalendars=muell

Does anybody know what’s wrong?

You had a bad configuration. Clear the cache and try again.