model.neuroml error

error

[2017-05-02 16:31:49.562] ERROR http-bio-8080-exec-7         org.apache.coyote.http11.Http11Protocol                           Error reading request, ignored java.lang.NullPointerException: null
	at org.geppetto.model.neuroml.modelInterpreterUtils.PopulateTypes.extractInfoFromComponent(PopulateTypes.java:265)
	at org.geppetto.model.neuroml.modelInterpreterUtils.PopulateTypes.createPopulationTypeVariable(PopulateTypes.java:439)
	at org.geppetto.model.neuroml.modelInterpreterUtils.PopulateTypes.extractInfoFromComponent(PopulateTypes.java:151)
	at org.geppetto.model.neuroml.modelInterpreterUtils.PopulateTypes.extractInfoFromComponent(PopulateTypes.java:82)
	at org.geppetto.model.neuroml.services.NeuroMLModelInterpreterService.extractTypes(NeuroMLModelInterpreterService.java:214)
	at org.geppetto.model.neuroml.services.LEMSModelInterpreterService.importType(LEMSModelInterpreterService.java:102)
	at org.geppetto.simulation.visitor.ImportTypesVisitor.caseImportType(ImportTypesVisitor.java:93)
	at org.geppetto.model.types.util.TypesSwitch.doSwitch(TypesSwitch.java:97)
	at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:53)
	at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:69)
	at org.geppetto.model.util.GeppettoModelTraversal.apply(GeppettoModelTraversal.java:60)
	at org.geppetto.simulation.manager.RuntimeProject.<init>(RuntimeProject.java:174)
	at org.geppetto.simulation.manager.GeppettoManager.loadProject(GeppettoManager.java:165)
	at org.geppetto.frontend.controllers.ConnectionHandler.loadGeppettoProject(ConnectionHandler.java:157)
	at org.geppetto.frontend.controllers.ConnectionHandler.loadProjectFromId(ConnectionHandler.java:114)
	at org.geppetto.frontend.controllers.WebsocketConnection.onTextMessage(WebsocketConnection.java:203)
	at org.apache.catalina.websocket.MessageInbound.onTextData(MessageInbound.java:78)
	at org.apache.catalina.websocket.StreamInbound.doOnTextData(StreamInbound.java:191)
	at org.apache.catalina.websocket.StreamInbound.onData(StreamInbound.java:139)
	at org.apache.coyote.http11.upgrade.UpgradeProcessor.upgradeDispatch(UpgradeProcessor.java:88)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:616)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)