NPE during attach in editable TreeTable

Hello,
  I navigate through different views. One of them contains editable TreeTable (see screenshot):

serviceList = new TreeTable("Menage services for roles:");
        serviceList.setTableFieldFactory(new DefaultFieldFactory(){
            @Override
            public Field<?> createField(Container container, final Object itemId,
                    final Object propertyId, Component uiContext) {
                CheckBox field = new CheckBox(Objects.toString(itemId));
                field.addValueChangeListener(event -> {
                    if (itemId instanceof ServiceDescriptor){
                        ServiceDescriptor service = (ServiceDescriptor) itemId;
                        if (field.getValue() != null && field.getValue()) {
                            field.addStyleName("blue");
                        }else{
                            field.removeStyleName("blue");
                        }
                    }else{//itemId instanceof ServiceGroup
                        for (Object service : serviceList.getContainerDataSource().getChildren(itemId)) {
                            serviceList.getContainerProperty(service, propertyId).setValue(event.getProperty().getValue());
                        }
                    }
                });
                field.addValueChangeListener(event -> {
                    if (systemChange){
                        return;
                    }
                    //some other staff
                });
                return field;
            }
        });
        serviceList.addValueChangeListener(event -> {
            Collection<?> value = (Collection<?>) event.getProperty().getValue();
            for (Object itemId : serviceList.getItemIds()) {
                if (itemId instanceof ServiceDescriptor) {
                    serviceList.getContainerProperty(itemId, "service").setValue(CollectionUtils.find(value, object -> {
                        return ((ServiceDescriptor) object).getKodSlu() == ((ServiceDescriptor) itemId).getKodSlu();
                    }) != null);
                }
            }
        });
        serviceList.setSizeFull();

Loading items to the tree table:

UI.getCurrent().access(() -> {
            HierarchicalContainer services = (HierarchicalContainer) serviceList.getContainerDataSource();
            synchronized (systemChange) {
                try {
                    systemChange = true;
                    services.removeAllItems();
                    for (ServiceDescriptor service : loadData()) {
                        ServiceGroup group = service.getServiceGroup();
                        if (!services.containsId(group)) {
                            services.addItem(group);
                            serviceList.setCollapsed(group, false);
                        }
                        services.addItem(service);
                        services.setChildrenAllowed(service, false);
                        services.setParent(service, group);
                    }
                } catch (Exception e1) {
                    error(e1);
                    showDBError(e1);
                } finally {
                    systemChange = false;
                }
            }
        });

And changing value (roleList is a table on the left on th screenshot):

roleList.addValueChangeListener(event -> {
            if (event.getProperty().getValue() == null
                    || statements.getStatement(Role_Statements.SELECT_SERVICE_BY_ROLE) == null) {
                return;
            }
            try {
                statements.getStatement(Role_Statements.SELECT_SERVICE_BY_ROLE).setValue(RoleFields.ROLE,
                        ((EnumValueDescriptor) event.getProperty().getValue()).getValue());
                ResultSet data = statements.getStatement(Role_Statements.SELECT_SERVICE_BY_ROLE).executeQuery();
                Collection<ServiceDescriptor> result = new ArrayList<>();
                while (data.next()) {
                    ServiceDescriptor service = FPSL_Statements.createServiceFromResultSet(data);
                    result.add(service);
                }
                synchronized (systemChange) {
                    systemChange = true;
                    serviceList.setValue(result);
                    systemChange = false;
                }
            } catch (Exception e) {
                error(e);
                showDBError(e);
            };
        });

Sometimes during navigation between views I get following exception:

com.vaadin.data.Buffered$SourceException
    at com.vaadin.ui.AbstractField.updateValueFromDataSource(AbstractField.java:1649)
    at com.vaadin.ui.AbstractField.attach(AbstractField.java:1374)
    at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:590)
    at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:621)
    at com.vaadin.ui.AbstractField.attach(AbstractField.java:1367)
    at com.vaadin.ui.AbstractSelect.attach(AbstractSelect.java:1872)
    at com.vaadin.ui.Table.attach(Table.java:4248)
    at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:590)
    at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:621)
    at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:590)
    at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:621)
    at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:590)
    at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:621)
    [b]at cz.pse.services.RolesView.attach(RolesView.java:99)
    at com.vaadin.ui.AbstractComponent.setParent(AbstractComponent.java:528)
    at com.vaadin.ui.AbstractSingleComponentContainer.setContent(AbstractSingleComponentContainer.java:149)
    at com.vaadin.ui.UI.setContent(UI.java:1276)
    at com.vaadin.navigator.Navigator$SingleComponentContainerViewDisplay.showView(Navigator.java:224)
    at com.vaadin.navigator.Navigator.navigateTo(Navigator.java:575)
    at com.vaadin.navigator.Navigator.navigateTo(Navigator.java:527)
    at cz.pse.services.ServicesView$7.menuSelected(ServicesView.java:457)[/b]
    at com.vaadin.ui.MenuBar.changeVariables(MenuBar.java:191)
    at com.vaadin.server.communication.ServerRpcHandler.changeVariables(ServerRpcHandler.java:486)
    at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:305)
    at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:184)
    at com.vaadin.server.communication.PushHandler$3.run(PushHandler.java:182)
    at com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:261)
    at com.vaadin.server.communication.PushHandler.access$200(PushHandler.java:58)
    at com.vaadin.server.communication.PushHandler$1.onRequest(PushHandler.java:78)
    at org.atmosphere.cpr.AsynchronousProcessor.action(AsynchronousProcessor.java:205)
    at org.atmosphere.cpr.AsynchronousProcessor.suspended(AsynchronousProcessor.java:104)
    at org.atmosphere.container.TomcatWebSocketUtil.doService(TomcatWebSocketUtil.java:154)
    at org.atmosphere.container.Tomcat7Servlet30SupportWithWebSocket.service(Tomcat7Servlet30SupportWithWebSocket.java:62)
    at org.atmosphere.cpr.AtmosphereFramework.doCometSupport(AtmosphereFramework.java:2075)
    at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:570)
    at org.atmosphere.websocket.DefaultWebSocketProcessor$3.run(DefaultWebSocketProcessor.java:332)
    at org.atmosphere.util.VoidExecutorService.execute(VoidExecutorService.java:101)
    at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:327)
    at org.atmosphere.websocket.DefaultWebSocketProcessor.invokeWebSocketProtocol(DefaultWebSocketProcessor.java:424)
    at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatchReader(DefaultWebSocketProcessor.java:794)
    at org.atmosphere.websocket.DefaultWebSocketProcessor.invokeWebSocketProtocol(DefaultWebSocketProcessor.java:526)
    at org.atmosphere.container.TomcatWebSocketHandler.onTextData(TomcatWebSocketHandler.java:104)
    at org.apache.catalina.websocket.StreamInbound.doOnTextData(StreamInbound.java:187)
    at org.apache.catalina.websocket.StreamInbound.onData(StreamInbound.java:135)
    at org.apache.coyote.http11.upgrade.UpgradeProcessor.upgradeDispatch(UpgradeProcessor.java:83)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:587)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at com.vaadin.data.util.IndexedContainer$IndexedContainerProperty.getValue(IndexedContainer.java:901)
    at com.vaadin.ui.AbstractField.getDataSourceValue(AbstractField.java:305)
    at com.vaadin.ui.AbstractField.updateValueFromDataSource(AbstractField.java:1639)
    ... 49 more

Does anybody have an idea why the excepion is araised and how to fix it?

My vaadin version is 7.4.8.