2017-08-02 11:30:14,971 ERROR .magnolia.ui.admincentral.AdmincentralErrorHandler: AdmincentralUI has encountered an unhandled exception.
com.vaadin.data.Buffered$SourceException
	at com.vaadin.ui.AbstractField.setPropertyDataSource(AbstractField.java:665)
	at info.magnolia.ui.form.field.AbstractCustomMultiField.createLocalField(AbstractCustomMultiField.java:176)
	at info.magnolia.ui.form.field.CompositeField.initFields(CompositeField.java:95)
	at info.magnolia.ui.form.field.CompositeField.initFields(CompositeField.java:57)
	at info.magnolia.ui.form.field.AbstractCustomMultiField.initFields(AbstractCustomMultiField.java:135)
	at info.magnolia.ui.form.field.CompositeField.initContent(CompositeField.java:82)
	at com.vaadin.ui.CustomField.getContent(CustomField.java:92)
	at com.vaadin.ui.CustomField.attach(CustomField.java:82)
	at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:619)
	at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:677)
	at com.vaadin.ui.AbstractComponent.setParent(AbstractComponent.java:584)
	at com.vaadin.ui.CustomField.getContent(CustomField.java:93)
	at com.vaadin.ui.CustomField.attach(CustomField.java:82)
	at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:619)
	at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:677)
	at com.vaadin.ui.AbstractComponent.setParent(AbstractComponent.java:584)
	at info.magnolia.editor.body.ContentBody.ensureComponentAttached(ContentBody.java:191)
	at info.magnolia.editor.body.ComponentBlockCommunicator.encodeBlock(ComponentBlockCommunicator.java:31)
	at info.magnolia.editor.body.ContentBody.encodeBlock(ContentBody.java:226)
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
	at info.magnolia.editor.body.ContentBody.beforeClientResponse(ContentBody.java:157)
	at com.vaadin.server.communication.UidlWriter.write(UidlWriter.java:112)
	at com.vaadin.server.communication.UidlRequestHandler.writeUidl(UidlRequestHandler.java:124)
	at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:92)
	at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
	at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1414)
	at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:365)
	at info.magnolia.ui.admincentral.AdmincentralVaadinServlet.service(AdmincentralVaadinServlet.java:146)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	at info.magnolia.cms.filters.ServletDispatchingFilter.doFilter(ServletDispatchingFilter.java:148)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.CompositeFilter.doFilter(CompositeFilter.java:65)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.virtualuri.VirtualUriFilter.doFilter(VirtualUriFilter.java:98)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.module.cache.executor.Bypass.processCacheRequest(Bypass.java:58)
	at info.magnolia.module.cache.executor.CompositeExecutor.processCacheRequest(CompositeExecutor.java:67)
	at info.magnolia.module.cache.filter.CacheFilter.doFilter(CacheFilter.java:220)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.i18n.I18nContentSupportFilter.doFilter(I18nContentSupportFilter.java:89)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.RangeSupportFilter.doFilter(RangeSupportFilter.java:77)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.security.BaseSecurityFilter.doFilter(BaseSecurityFilter.java:57)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.security.SecurityCallbackFilter.doFilter(SecurityCallbackFilter.java:84)
	at info.magnolia.cms.filters.OncePerRequestAbstractMgnlFilter.doFilter(OncePerRequestAbstractMgnlFilter.java:59)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.security.LogoutFilter.doFilter(LogoutFilter.java:94)
	at info.magnolia.cms.filters.OncePerRequestAbstractMgnlFilter.doFilter(OncePerRequestAbstractMgnlFilter.java:59)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.module.site.filters.SiteMergeFilter.doFilter(SiteMergeFilter.java:119)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.multisite.filters.MultiSiteFilter.doFilter(MultiSiteFilter.java:110)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.MultiChannelFilter.doFilter(MultiChannelFilter.java:83)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.module.cache.filter.GZipFilter.doFilter(GZipFilter.java:73)
	at info.magnolia.cms.filters.OncePerRequestAbstractMgnlFilter.doFilter(OncePerRequestAbstractMgnlFilter.java:59)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.security.auth.login.LoginFilter.doFilter(LoginFilter.java:127)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.enterprise.registration.RegistrationFilter.doFilter(RegistrationFilter.java:64)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.personalization.preview.filter.PreviewFilter.doFilter(PreviewFilter.java:92)
	at info.magnolia.cms.filters.OncePerRequestAbstractMgnlFilter.doFilter(OncePerRequestAbstractMgnlFilter.java:59)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:81)
	at info.magnolia.cms.filters.ContentTypeFilter.doFilter(ContentTypeFilter.java:155)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.ContextFilter.doFilter(ContextFilter.java:128)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:79)
	at info.magnolia.cms.filters.CompositeFilter.doFilter(CompositeFilter.java:65)
	at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:85)
	at info.magnolia.cms.filters.SafeDestroyMgnlFilterWrapper.doFilter(SafeDestroyMgnlFilterWrapper.java:107)
	at info.magnolia.cms.filters.MgnlFilterDispatcher.doDispatch(MgnlFilterDispatcher.java:67)
	at info.magnolia.cms.filters.MgnlMainFilter.doFilter(MgnlMainFilter.java:108)
	at info.magnolia.cms.filters.MgnlMainFilter.doFilter(MgnlMainFilter.java:94)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:1110)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:785)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1425)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
Caused by: com.vaadin.data.util.converter.Converter$ConversionException: Unable to convert value of type java.util.LinkedList to presentation type interface java.util.Set. No converter is set and the types are not compatible.
	at com.vaadin.data.util.converter.ConverterUtil.convertFromModel(ConverterUtil.java:118)
	at com.vaadin.ui.AbstractField.convertFromModel(AbstractField.java:736)
	at com.vaadin.ui.AbstractField.convertFromModel(AbstractField.java:721)
	at com.vaadin.ui.AbstractField.setPropertyDataSource(AbstractField.java:657)
	... 127 more