Update from 3 to 4 no sitemap Works

After Update from 3 to 4 no Sitemap works:

2023-10-18 21:10:51.671 [ERROR] [omponents.UIComponentSitemapProvider] - Cannot build sitemap page_83b70da4cb
java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.Collection (java.lang.String and java.util.Collection are in module java.base of loader ‘bootstrap’)
at org.openhab.core.ui.internal.components.UIComponentSitemapProvider.addIconRules(UIComponentSitemapProvider.java:438) ~[bundleFile:?]
at org.openhab.core.ui.internal.components.UIComponentSitemapProvider.buildWidget(UIComponentSitemapProvider.java:302) ~[bundleFile:?]
at org.openhab.core.ui.internal.components.UIComponentSitemapProvider.buildSitemap(UIComponentSitemapProvider.java:167) ~[bundleFile:?]
at org.openhab.core.ui.internal.components.UIComponentSitemapProvider.getSitemapNames(UIComponentSitemapProvider.java:126) ~[bundleFile:?]
at org.openhab.ui.basic.internal.render.PageRenderer.renderSitemapList(PageRenderer.java:223) ~[?:?]
at org.openhab.ui.basic.internal.servlet.WebAppServlet.showSitemapList(WebAppServlet.java:123) ~[?:?]
at org.openhab.ui.basic.internal.servlet.WebAppServlet.service(WebAppServlet.java:155) ~[?:?]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:584) ~[bundleFile:4.0.4]
at org.ops4j.pax.web.service.spi.servlet.OsgiInitializedServlet.service(OsgiInitializedServlet.java:102) ~[bundleFile:?]
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1656) ~[bundleFile:9.4.52.v20230823]
at org.ops4j.pax.web.service.spi.servlet.OsgiFilterChain.doFilter(OsgiFilterChain.java:100) ~[bundleFile:?]
at org.ops4j.pax.web.service.jetty.internal.PaxWebServletHandler.doHandle(PaxWebServletHandler.java:320) ~[bundleFile:?]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:600) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:234) ~[bundleFile:9.4.52.v20230823]
at org.ops4j.pax.web.service.jetty.internal.PrioritizedHandlerCollection.handle(PrioritizedHandlerCollection.java:96) ~[bundleFile:?]
at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:731) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.Server.handle(Server.java:516) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487) ~[bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883) [bundleFile:9.4.52.v20230823]
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034) [bundleFile:9.4.52.v20230823]
at java.lang.Thread.run(Thread.java:833) [?:?]

I deleted all sitemaps and created a simple one, so that I can exclude errors in the sitemaps. What could be my problem?

What Java version is installed, OpenHab 4 need Java 17.

And is this with OH 4.0.3 or 4.1 snapshot?

yes java 17 is installed:
openhabian@openhabian:~ $ java --version
openjdk 17.0.7 2023-04-18
OpenJDK Runtime Environment (build 17.0.7+7-Raspbian-1deb11u1rpt1)
OpenJDK Client VM (build 17.0.7+7-Raspbian-1deb11u1rpt1, mixed mode, emulated-client)

und openhab ist version:
openHAB 4.1.0
Build #3679

Known issue in 4.1M2 and recent 4.1 snapshots for sitemaps generated with MainUI.

Thanks for the information, I have upgraded to the openHAB 4.1.0
Build #3681, there seems to be the error still.

Follow issue in Github to know when it will be fixed: