Unable to create system map

Clicking on the gateway Status button, i get this red error:
Unable to create system map. See log for details.
And the console gives this

Time Logger Message [ERROR] 12.37.26 SysMapPanel$ClusterMapsModel Unable to create system map. java.lang.NullPointerException at com.inductiveautomation.xopc.server.core.XOPCGatewayHook.updateSystemMap(XOPCGatewayHook.java:499) at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl.updateSystemMap(ModuleManagerImpl.java:781) at com.inductiveautomation.ignition.gateway.SRContext.getSystemMap(SRContext.java:2362) at com.inductiveautomation.ignition.gateway.SRContext.getSystemMaps(SRContext.java:2371) at com.inductiveautomation.ignition.gateway.web.pages.status.SysMapPanel$ClusterMapsModel.load(SysMapPanel.java:196) at com.inductiveautomation.ignition.gateway.web.pages.status.SysMapPanel$ClusterMapsModel.load(SysMapPanel.java:191) at org.apache.wicket.model.LoadableDetachableModel.getObject(LoadableDetachableModel.java:121) at org.apache.wicket.Component.getDefaultModelObject(Component.java:1615) at org.apache.wicket.markup.html.list.ListView.getViewSize(ListView.java:219) at org.apache.wicket.markup.html.list.ListView.onPopulate(ListView.java:473) at org.apache.wicket.markup.repeater.AbstractRepeater.onBeforeRender(AbstractRepeater.java:116) at org.apache.wicket.Component.internalBeforeRender(Component.java:922) at org.apache.wicket.Component.beforeRender(Component.java:990) at org.apache.wicket.MarkupContainer.onBeforeRenderChildren(MarkupContainer.java:1680) at org.apache.wicket.Component.onBeforeRender(Component.java:3830) at org.apache.wicket.Component.internalBeforeRender(Component.java:922) at org.apache.wicket.Component.beforeRender(Component.java:990) at org.apache.wicket.MarkupContainer.onBeforeRenderChildren(MarkupContainer.java:1680) at org.apache.wicket.Component.onBeforeRender(Component.java:3830) at org.apache.wicket.Component.internalBeforeRender(Component.java:922) at org.apache.wicket.Component.beforeRender(Component.java:990) at org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:938) at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:173) at com.inductiveautomation.ignition.gateway.web.components.SideTabbedPanel.setSelectedTab(SideTabbedPanel.java:304) at com.inductiveautomation.ignition.gateway.web.components.SideTabbedPanel.onBeforeRender(SideTabbedPanel.java:191) at org.apache.wicket.Component.internalBeforeRender(Component.java:922) at org.apache.wicket.Component.beforeRender(Component.java:990) at org.apache.wicket.MarkupContainer.onBeforeRenderChildren(MarkupContainer.java:1680) at org.apache.wicket.Component.onBeforeRender(Component.java:3830) at org.apache.wicket.Page.onBeforeRender(Page.java:802) at com.inductiveautomation.ignition.gateway.web.pages.BasePage.onBeforeRender(BasePage.java:150) at com.inductiveautomation.ignition.gateway.web.pages.AuthenticatedPage.onBeforeRender(AuthenticatedPage.java:96) at org.apache.wicket.Component.internalBeforeRender(Component.java:922) at org.apache.wicket.Component.beforeRender(Component.java:990) at org.apache.wicket.Component.internalPrepareForRender(Component.java:2204) at org.apache.wicket.Page.internalPrepareForRender(Page.java:247) at org.apache.wicket.Component.render(Component.java:2289) at org.apache.wicket.Page.renderPage(Page.java:1021) at org.apache.wicket.request.handler.render.WebPageRenderer.renderPage(WebPageRenderer.java:116) at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:244) at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:165) at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:814) at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64) at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:253) at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:210) at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:281) at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188) at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:245) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Unknown Source)
Modules bugs? Any suggestion?
Thank you

What version of Ignition is this?

Version 7.6.4 (b2013112117)
Java Version Oracle Corporation 1.7.0_25

Looks like this may have been fixed in 7.6.5 and later.