org.tupeloproject.kernel.OperatorException: unknown operator failure
at org.tupeloproject.kernel.Kernel.invokeMethodOnOperator(Kernel.java:162)
at org.tupeloproject.kernel.Kernel.perform(Kernel.java:189)
at org.tupeloproject.kernel.Context.perform(Context.java:51)
at org.tupeloproject.kernel.BaseContext.performWith(BaseContext.java:271)
at org.tupeloproject.sql.SqlContext.doPerform(SqlContext.java:582)
at sun.reflect.GeneratedMethodAccessor548.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.tupeloproject.kernel.Kernel.invokeMethodOnOperator(Kernel.java:151)
at org.tupeloproject.kernel.Kernel.perform(Kernel.java:189)
at org.tupeloproject.kernel.Context.perform(Context.java:51)
at org.tupeloproject.kernel.RoutingContext.perform(Unknown Source)
at org.tupeloproject.kernel.SubjectSession.fetchSubject(SubjectSession.java:93)
at org.tupeloproject.kernel.SubjectSession.getSubject(SubjectSession.java:192)
at org.tupeloproject.kernel.SubjectSession.getValue(SubjectSession.java:739)
at edu.uiuc.ncsa.cet.bean.tupelo.TupeloBeanUtil.get(Unknown Source)
at edu.uiuc.ncsa.cet.bean.tupelo.TupeloBeanUtil.get(Unknown Source)
at edu.uiuc.ncsa.cet.bean.tupelo.TupeloBeanUtil.get(Unknown Source)
at edu.uiuc.ncsa.cet.bean.tupelo.TupeloBeanUtil.get(Unknown Source)
at edu.illinois.ncsa.mmdb.web.server.dispatch.ListDatasetsHandler.listDatasets(ListDatasetsHandler.java:83)
at edu.illinois.ncsa.mmdb.web.server.dispatch.ListDatasetsHandler.execute(ListDatasetsHandler.java:95)
at edu.illinois.ncsa.mmdb.web.server.dispatch.ListDatasetsHandler.execute(ListDatasetsHandler.java:1)
at net.customware.gwt.dispatch.server.DefaultDispatch.doExecute(DefaultDispatch.java:78)
at net.customware.gwt.dispatch.server.DefaultDispatch.execute(DefaultDispatch.java:68)
at net.customware.gwt.dispatch.server.service.DispatchServiceServlet.execute(DispatchServiceServlet.java:24)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:562)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:188)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:224)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at edu.illinois.ncsa.mmdb.web.server.MyDispatchServiceServlet.service(MyDispatchServiceServlet.java:34)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)
Caused by: java.lang.ClassCastException: org.tupeloproject.rdf.UriRef cannot be cast to org.tupeloproject.rdf.Literal
at org.tupeloproject.sql.SqlContext.fromSqlString(SqlContext.java:88)
at org.tupeloproject.sql.SqlContext.unify(SqlContext.java:337)
at org.tupeloproject.sql.SqlContext.doPerform(SqlContext.java:367)
at sun.reflect.GeneratedMethodAccessor537.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.tupeloproject.kernel.Kernel.invokeMethodOnOperator(Kernel.java:151)
... 52 more