Error loading basic / classic ui

Hi,

Has anyone seen this before - I get the following each time I try load classic, or basic ui - both have been removed and re-installer using karaf console.

HTTP ERROR 500

Problem accessing /basicui/app. Reason:

Server Error

Caused by:

java.lang.NoSuchMethodError: org.eclipse.smarthome.ui.items.ItemUIRegistry.getChildren(Lorg/eclipse/smarthome/model/sitemap/Sitemap;)Lorg/eclipse/emf/common/util/EList;
at org.eclipse.smarthome.ui.basic.internal.servlet.WebAppServlet.service(WebAppServlet.java:151)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)
at org.ops4j.pax.web.service.jetty.internal.HttpServiceServletHandler.doHandle(HttpServiceServletHandler.java:71)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
at org.ops4j.pax.web.service.jetty.internal.HttpServiceContext.doHandle(HttpServiceContext.java:287)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:80)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:499)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
at java.lang.Thread.run(Thread.java:745)

Stop OH

Remove the contents of /var/lib/openhab2/cache and /var/lib/openhab2/tmp

Start OH

That usually fixes this error.

Thanks Rich - busy upgrading to a newer release - @Benjy dropped me a super writeup over at Upgrade from 2.0.0 to 2.1.0
Assuming this does not resolve the basic / classic issue, I’ll try clear the cache out manually and get back to you.

Thanks for the prompt response

Clearing the cache may temporarily fix it (or not :frowning: )

Do we know what causes this error and how do we stop it from recurring?

thanks,
Mark